Fullscreen HTML5Med Res (??MB)HTML4

Programmable mains timer with remote switching Remote-controlled mains switches are very convenient but what if you could add a versatile easy-to-program timer to one of these units? Well, now you can. This Remote Switch Timer can be programmed to switch the power on and off after a set period or to switch the power on and off at set times. By JOHN CLARKE M AINS TIMERS are ideal for switching appliances on or off at predetermined times. Their complexity ranges from simple mechanical timers with a synchronous motor and switch actuator cams through to complex menu-driven fully-electronic timers which tend to have fiddly buttons and can be difficult to program. However, none have the advantage of remote control, whereby the timer is remote from the actual mains-switched power socket. To give an example, say you have an appliance in your garage that you want to control with a mains timer. Wouldn’t it be nice if you could pro66  Silicon Chip gram and control the timer without having to be in the garage? This idea can be extended to a lot of applications. To meet this need, we’ve devised this “Remote Switch Timer”. It’s designed to work with just about any commercially-available remote control mains socket (provided the hand-held remote is powered by a 12V battery). Basically, it interfaces with the remote’s PCB and provides the extra timing functions. The remote then automatically switches the mains socket on and off, as required. As shown in the photos, the Remote Switch Timer is housed in a plastic box, along with the PCB from the remote. It has 10 pushbutton switches and a 2-line LCD which has a dimmable backlight for night-time use. The front-panel buttons are used to program and control the unit. Remote control mains sockets For those unfamiliar with these devices, a remote control mains socket consists of a mains plug and piggyback socket, together with a relay and UHF receiver inside the plastic housing. It is controlled using a UHF hand-held remote control which is used to switch the mains socket on and off. Both 3-channel and 8-channel siliconchip.com.au The Jaycar remote controlled mains switch comes with a 3-channel hand-held remote. The MS-6142 comes with a three mains sockets, while the MS-6145 has one socket. remotes are typically available and these come either with a single socket or with a number of sockets. Alternatively, the additional sockets have to be purchased separately. The remote controls each socket individually and it’s just a matter of either using a learning procedure to set the socket’s channel number of setting a channel switch on the rear of the socket. The Altronics A0340, Jaycar MS6145 and Jaycar MS-6142 are typical of the units currently available. How does it work? The SILICON CHIP Remote Switch Timer is designed to activate any pair of on/off switches on the remote control. It does this by controlling two small relays which have their contacts wired across the desired on and off switches on the remote’s PCB. Basically, it’s just a matter of removing the remote’s PCB from its case and housing it together with the Remote Switch Timer inside a plastic utility case. The two are then wired together and powered from an external 12V DC plugpack and an optional internal 9V back-up battery. As well as using the new automatic timing functions, you can still manually control the mains socket using separate On and Off pushbuttons on the Remote Switch Timer. Alternatively, another hand-held remote can be used. In preset-time mode, the Remote Switch Timer is used to send an on or siliconchip.com.au The Altronics A0340 has an 8-channel remote control and is supplied with a single mains socket. Additional mains sockets can be purchased separately. off signal to the remote mains socket after a set period of time. You simply program when you want the socket to switch on or off and then press the Set/ Start button. The timer then automatically switches after the preset time, which can range from a minimum of one minute to a maximum of 255 hours and 59 minutes (that’s more than 10 days!). During the time-out period, the displayed time decreases by one every minute until the timer reaches zero. The relay for that timer function then closes and the UHF signal from the remote is sent to the mains socket. To set the time-out period, you first select either the On or Off timer using the Next pushbutton. The separate Up and Down hours and minutes pushbuttons are then used to set the required timing period. If you want more complexity, the Remote Switch Timer can use both its timers. One timer can be set to turn the mains socket on after a preset time, while the other can be set to then turn it off (or vice versa). In addition, the On and Off pushbuttons can be used to set the initial status of the remote control mains socket; ie, you can start with the mains power on or off. Default timing cycle The default timing cycle for the unit is for it to run once only. This is where the timers are set to their required values and decrease over time until they reach zero. Once a timer has counted down to zero, there is no more control from that timer unless it’s set to a new value. Note that the timer will just show dashes when the time-out is zero. The default setting can be changed from “once only” to “repeat”. This is where the timers are returned to their original settings after both timers have timed out. As an example, let’s say that you’ve set the On timer to two minutes and the Off timer to three minutes. This means that after two minutes, the On timer will have counted down to zero and sent an “on” signal to the mains socket to turn on the power. The Off timer now continues to count down and when it too reaches zero (ie, after one minute more), an “off” signal will be sent to the mains socket. Both timers will then be reset to their original 2-minute and 3-minute settings and so the cycle repeats every three minutes. The on and off timers for this countdown style of timing are called the “ON IN” and “OFF IN” timers (ie, on in a certain period and off in a certain period). The once only and repeat timer options are predictably named “ONCE ONLY” and “REPEAT”. This style of timer is quite useful (and simple to use) for many timer applications. However, for even more flexibility, a “real-time” timer mode is also included. This is similar to setting an alarm clock and allows you to set the time of day for the on/off switching to occur. November 2014  67 Parts List 1 double-sided, plated-through PCB, code 19112141, 104 x 76mm 1 front panel PCB, code 19112142, 157 x 94mm* OR 1 front panel label, 144 x 84mm* 1 UB1 plastic utility case, 158 x 95 x 53mm* 6 M3 x 9mm tapped spacers* 1 LCD module with backlighting (Altronics Z-7013, Jaycar QP5512) 1 UHF remote-controlled mains switch with 12V powered remote controls (eg, Altronics A0340, Jaycar MS-6145, MS6142) 2 SPST DIP 5V reed relays (Altronics S4100A, Jaycar SY4030) (RLY1,RLY2) 1 4MHz low-profile crystal (HC49US case) (X1) 10 click-action pushbutton PCB switches (white) (Jaycar SP0723, Altronics S1099) 1 12V DC plugpack (100mA or greater) 1 16-way SIL pin header with 2.54mm pin spacing 1 panel-mount DC socket (2.1 or 2.5mm to suit plugpack) 4 2-way polarised headers (2.54mm pin spacing) 4 2-way polarised header plugs (2.54mm pin spacing) (CON1CON4) 12 M3 x 5mm machine screws (2 preferably countersunk for the rear of the box) 1 100mm cable tie 1 400mm length of medium-duty black hook-up wire 1 200mm length of medium-duty red hook-up wire Semiconductors 1 PIC16F88-I/P microcontroller programmed with 1911214A. hex (IC1) 1 LP2950ACZ-5.0 low-dropout 5V regulator (REG1) 1 BC337 NPN transistor (Q1) 6 1N4148 diodes (D1,D2,D4-D7) 2 1N4004 1A diodes (D3,D8) Capacitors 2 10µF 16V PC electrolytic 1 100nF MKT polyester 2 33pF C0G (NP0) ceramic Resistors (0.25W, 1%) 1 100kΩ 1 330Ω 0.5W 1 10kΩ 2 100Ω 1 2.2kΩ 1 10kΩ miniature horizontal trimpot (VR1) *Alternative enclosure parts 1 sealed polycarbonate case with clear lid 115 x 90 x 55mm (Jaycar HB-6246 or similar) 1 front panel label, 103 x 78mm 4 M3 x 12mm tapped spacers Optional parts for battery back-up 1 9V battery snap with lead (Jaycar PH-9232, Altronics P 0455) 1 9V battery (522/6LR61) 1 9V U-clamp battery holder (Jaycar PH-9237, Altronics S 5050) 1 2-way polarised header & plug (2.54mm pin spacing) (CON5) 1 M3 x 6mm machine screw 1 M3 nut selection as to whether you want a timer to be operational or not. There are two possible settings for real-time switching: (1) where the sequence occurs once only; and (2) where the on and off cycle is repeated each day. As before, these options are called “ONCE ONLY” and “REPEAT”. For the once only selection, the timer will revert to zero (with the LCD showing dashes) once that timer has matched the clock. For the repeat selection, the timer will remain at its time setting so that it can repeat the switching sequence each day. Clock accuracy The long-term timing accuracy depends on the accuracy of the crystal timebase used in the Remote Switch Timer. This in turn is dependent of the crystal tolerance and on temperature variations throughout the year. For a standard ±50ppm crystal, the clock could be fast or slow by up to 130s (ie, two minutes & 10 seconds) over a period of 30 days. However, the timing accuracy can be easily adjusted by changing a value in the software that runs in the PIC microcontroller used in the Remote Switch Timer. Basically, the can be adjusted to run faster or slower in 1ppm steps, up to a maximum of ±99ppm. A 1ppm change represents about 2.6s in 30 days, while the 99ppm maximum adjustment corresponds to 256s in 30 days. Adjusting the clock accuracy may be necessary if you want the “ON AT” and “OFF AT” timers to switch the unit at certain times of the day. However, it will not usually be necessary for the “ON IN” and “OFF IN” timers which are used to switch the unit in a certain time period. Battery back-up In order to do this, a real time clock is required and the one used here is in 24-hour format. Real-time switching For this mode, we call the real-time timers “ON AT” and “OFF AT” (ie, on at a certain time and off at a certain time). You can set either one timer or both. The timers are also in 24-hour format and are compared against the time on the clock. When the clock and timers match, an on or off signal is sent to the mains socket. Note that in this mode, the timer values do not change during the time68  Silicon Chip out period. Instead, they are simply compared with the clock for a timeout match. Note that a 00h:00m setting for either timer will show as dashes on the LCD and there is no on or off switching for this setting. 00h:00m also corresponds to midnight, so it is not possible to have the timer switch at precisely midnight. However, switching times one minute before (23h 59m) and one minute after midnight (0h 1m) are possible. This rather minor shortcoming allows for simplified timer operation because it doesn’t require an extra An option is to include a battery back-up for the Remote Switch Timer. That way, all settings will be retained and timing will continue in the event of a black-out or if mains power is removed from the unit. Of course, the mains socket will not be powered in the event of a blackout and so it will not respond to any on or off signals from the unit. However, when power is restored, the last on or off signal is sent again after a short delay. That way, the mains socket will switch to the required setting for the present time. Note that the backlighting for the siliconchip.com.au siliconchip.com.au K A 1N4004 7,8 2 RLY 2 100Ω C K A 1N4148 33pF OSC1 16 15 OSC2 RB1 Vss 5 RB5 RB4 11 RB2 8 S10 S9 A S5 D7 REMOTE SWITCH TIMER S8 S3 S4 K A S7 D6 S2 K A S6 D5 K A D4 S1 SC S1: S2: S3: S4: S5: 4 14 13 12 11 6 7–10 5 1 4x 1N4148 K 20 1 4 HOUR UP HOUR DOWN MINUTES UP MINUTES DOWN SET/START S6: NEXT S7: CYCLE S8: ON S9: OFF S10: BACKLIGHT 10 RB0 6 RA2 RA3 1 RA4 2 3 18 RA1 IC1 PIC16F88 PIC1 6F8 8 RB6 RA0 7 12 17 RB3/PWM Vdd RA5/MCLR RB7 13 LED 16 CATHODE D7 D6 D5 D4 EN RS GND R/W D0–D3 3 CONTRAST 16 x 2 LCD MODULE Vdd 2 LED 15 ANODE LCD CONTRAST 10k VR1 10k 330 Ω 1W 4 14 9 100nF 2.2k B X1 4.0MHz E 33pF Q1 BC337 C 100Ω E B BC 33 7 D2 1N4148 K A 6 2 A D1 1N4148 (POWER DETECT) 10V 10 µF +5V Fig.1: the circuit is based on PIC16F88-I/P microcontroller IC1 and an LCD module. IC1 monitors switches S1-S10, drives the LCD, controls the timing and drives miniature relays RLY1 & RLY2. The relays have their contacts wired across the On and Off buttons of a UHF remote control module. OUT IN GND LP2950 UHF REMOTE OFF SWITCH 1,14 7,8 1,14 RLY 1 K 100k GND IN OUT REG1 LP2950ACZ–5.0 16V 10 µF 6 Circuit details Take a look now at Fig.1 for the circuit details of the Remote Switch Timer. It’s quite simple and is based on a PIC16F88-I/P microcontroller (IC1), an LCD module, a couple of miniature relays, 10 pushbutton switches and a few other parts. Most of the complexity is hidden inside the software that’s programmed into IC1. This allows the micro to monitor the switch inputs and drive the LCD module and relays according to the actions required by the switches and internal timers. IC1’s RA2, RA3, RA4 & RB0 data lines send character data to the LCD module. In addition, the RA1 & RB7 lines drive the Enable (EN) and Register Select (RS) inputs. The LCD is set to run using four bits of data to save on outputs from IC1. The necessary data bits are sent to the LCD as two separate transfers, to make up the eight bits necessary to fully drive the display. The RA2, RA3, RA4 & RB0 lines also drive a matrix based on pushbutton switches S1-S10 and diodes D4-D7. To check if a switch is closed, the RA2, RA3, RA4 & RB0 lines are driven low and the RB2, RB4 & RB5 inputs monitored. These latter inputs are normally pulled high (to +5V) via internal pullups but one of these inputs will go low (ie, close to 0V) if a switch is closed. When a low is detected, the RA2, RA3, RA4 & RB0 lines are taken high again and then taken low one at a time while IC1 continues monitoring RB2, RB4 & RB5. This allows the micro to determine which switch button is being pressed. For example, if S3 is closed, this will be detected when RA4 goes low and in turn pulls RB4 low. Diodes D4-D7 are there to prevent shorts between the RA2, RA3, RA4 & RB0 lines if two switches are pressed at the same time. Shorts between these lines would not only affect switch detection but would also affect the drive CON2 CON1 + – CON4 CON5 A K D8 1N4004 UHF REMOTE ON SWITCH UHF REMOTE SUPPLY (OPTIONAL) + – TO 9V BATTERY SNAP 12V DC TO SOCKET + – CON3 A K D3 1N4004 LCD module is switched off to conserve the battery when the unit is running from battery power alone. Without battery back-up, the Remote Switch Timer will reset with all timers set to zero when a black-out ends. In addition, the mains socket will be reset with the power off. In summary, it’s an incredibly versatile unit that’s easy to program. It should cover a very wide range of timing applications. November 2014  69 ON 14121191 H CLCD TI WMODULE S S NIA M F HZ-7013 U R OF R(B/L) E MI T 16X2 ALTRONICS RLY1 SY4030 D1 OFF 4148 4004 4148 D6 4148 D7 UP HOURS S1 BACKLIGHT VR1 10k 100nF IC1 PIC16F88–I/P 10k DOWN 100Ω UP S2 S3 Q1 S7 S8 CYCLE ON S6 S9 NEXT DOWN MINUTES S4 S5 OFF SET/START TIMER FOR UHF MAINS SWITCHES FRONT VIEW TO REMOTE’S ON SWITCH CON1 19112141 TIMER FOR UHF MAINS SWITCH (LCD MODULE UNDER) CON2 TO REMOTE’S OFF SWITCH DC INPUT SOCKET UHF – + SUPPLY POWER FOR UHF REMOTE GND CON4 CON3 (IC1 UNDER) +12V D5 S10 100Ω D2 4148 SUPPLY + – 330Ω 19112141 C 2014 D4 4148 UHF 2.2k 33pF 10 µF 33pF 4148 4004 + – Backup CONTRAST 100k D8 4MHz BC337 D3 X1 GND LP2950 ACZ-5.0 +12V REG1 10 µF RLY2 SY4030 14 13 12 11 10 9 8 7 6 5 4 3 2 1 16 15 CON5 – STRESS RELIEF HOLES FOR BATTERY SNAP LEADS + FOR 9V BATTERY SNAP LEAD (OPTIONAL) REAR VIEW Fig.2: install the parts on PCB as shown here. Be sure to use a socket for IC1 and make sure that all polarised parts are correctly orientated. The 2-way header sockets (CON1-CON5) are the only parts that mount on the rear of the board. signals to the LCD and cause corrupted characters to be displayed. Ports RB1 & RB6 drive relays RLY1 & RLY2 via 100Ω resistors. The NO (normally open) contacts of the relays go to CON1 & CON2 and these in turn are wired in parallel with the ON and OFF switches respectively on the UHF remote’s PCB. Diodes D1 & D2 are there to prevent damage to RB1 & RB6 by clamping the back-EMF generated by the coils when the relays switch off. The 100Ω resistors in series with the relay coils also help protect IC1’s RB1 & RB6 outputs. They are not needed 70  Silicon Chip in normal operation but will limit the back-EMF current from a relay coil if its associated diode fails or develops a dry joint connection. Timing A 4MHz crystal (X1) between pins 15 & 16 of IC1 is used to provide an accurate reference for the timing oscillator. It’s loaded with fixed 33pF capacitors to ensure it starts correctly. Normally, the crystal would be trimmed to a precise 4MHz using a trimmer capacitor in place of one of the fixed values. However, without suitable calibrated test equipment, it’s not possible to accurately adjust the trimmer without a great deal of trial and error. As a result, as previously stated, we chose to use a software adjustment procedure instead. If the 4MHz crystal is precisely on frequency, the program runs at exactly 1MHz. The software uses a counter (Timer1) that overflows after a count of 40,000 or after 1/25th of a second if the clock frequency is precisely 1MHz (ie, 25 of these 40,000 counts will take 1s). If the crystal runs too fast or too slow, it’s just a matter of altering the 40,000 number used in the counter to provide the correct 1s period. For example, for a 1ppm adjustment, the number for Timer1’s overflow counter must either be 40,001 (ie, one more) if the crystal is too fast or 39,999 (ie, one less) if the crystal is too slow. Note that this change is only done for one of the 25 overflow counts that make up one second for Timer1. The remaining 24 counts still use 40,000 as the count. As stated, the overall adjustment range is from -99ppm to +99ppm. In operation, the software then adds or subtracts the ppm correction value from 40,000 in order to compensate for the crystal frequency. The overflow ppm adjustment is done via the front-panel switches as described later, with the setting shown on the LCD. The correction required is determined by comparing the time of the Remote Switch Timer against a known accurate clock over a set period. Each 2.592 seconds in 30 days that it is off is equivalent to 1ppm. Note that the clock on the Remote Switch Timer shows the seconds, so that the clock’s accuracy can be checked. The timing functions, however, are only to the nearest minute. Backlighting Backlighting is provided for the LCD so that the timer can be used in the dark. This can be adjusted in 16 steps from fully off through to full brightness by pressing the Backlight pushbutton (S10). This brings up the backlighting value which is shown as a number ranging from 0-15, with 15 being full brightness. A bargraph is also used to show the brightness setting. For brightness levels between 1-14, the backlight LEDs are driven using PWM (pulse width modulation). Pin 9 (PWM) of IC1 provides the PWM siliconchip.com.au to power up and for the companion mains socket to power up if there has been a blackout. Construction All the parts (except for the UHF remote) are installed on a PCB coded 19112141 and measuring 104 x 76mm. Fig.2 shows the parts layout on the PCB. Begin by installing the resistors and diodes. Table 1 shows the resistor colour codes but we recommend that you also check each one using a DMM before installing it. Be sure to install the diodes with the correct polarity. REG1 and Q1 are next on the list. These two devices look the same, so be careful not to get them mixed up. Once they’re in, install an 18-pin socket for IC1, with the notched end towards D5. Follow with the capacitors. The two 10µF electrolytics must be installed with the polarity shown and bent over so that they lie flat against the PCB, so that they later sit below the top edge of the LCD module (see photo). The ceramic and MKT capacitors can be mounted either way around. Crystal X1 and trimpot VR1 can now go in, followed by the two relays. Note that each relay must be installed with its notched end towards the LCD. Now for the LCD module. This is mounted using a 16-way SIL pin header at the bottom lefthand edge. Begin by fitting the header in place with its short pins going into the PCB. Solder these pins, then fit the LCD module over the longer pins and push it all the way down before soldering these pins as well. The 10 pushbutton switches can now be installed. These go in with The completed timer PCB. Note how the two 10μF electrolytic capacitors are bent over so that they don’t later foul the lid of the case. waveform and this drives the cathodes of the backlight LEDs via transistor Q1 and a 330Ω current-limiting resistor. For level 0, there is no drive to the LED cathodes (Q1 permanently off) and for level 15, the LEDs are continuously driven (Q1 permanently on). At other levels, the duty cycle of the PWM pulse determines the LED brightness. At half brightness, for example, the LEDs are switched on and off via Q1 using a 50% duty cycle. The PWM frequency is 66.66kHz, so the on and off switching of the LEDs will not be noticeable. The contrast of the LCD module is adjusted using VR1. It’s just a matter of tweaking VR1 to suit. Power supply The Remote Switch Timer is normally powered from a 12V DC plugpack supply connected to CON3. Diode D3 provides reverse polarity protection and the nominal 11.4V supply rail is then filtered using a 10µF capacitor and used to power the backlight LEDs in the LCD module. The 11.4V rail is also fed to lowdropout regulator REG1. This produces a regulated 5V rail to power microcontroller IC1, the LCD module and the remaining circuitry. The optional 9V back-up battery is connected to CON5. Diode D8 provides reverse polarity protection and both it and D3 isolate the two supplies. IC1’s RA0 input (pin 17) monitors the 12V supply line from CON3. If this goes to 0V but IC1 is still powered via the back-up battery, the software detects this loss of 12V power and switches off the backlight. When the 12V is subsequently restored, this is detected by RA0 and the last ON or OFF signal is resent to the remote PCB by turning on the appropriate relay. In practice, the ON or OFF relay is activated about 3s after power is restored and remains on for around 900ms. This 3s delay gives enough time for the remote control circuit Table 2: Capacitor Codes Value µF Value IEC Code EIA Code 100nF   0.1µF 100n 104 33pF   NA   33p   33 Table 1: Resistor Colour Codes o o o o o o siliconchip.com.au No.   1   1   1   1   2 Value 100kΩ 10kΩ 2.2kΩ 330Ω 100Ω 4-Band Code (1%) brown black yellow brown brown black orange brown red red red brown orange orange brown brown brown black brown brown 5-Band Code (1%) brown black black orange brown brown black black red brown red red black brown brown orange orange black black brown brown black black black brown November 2014  71 0V TO CON4 +12V TO CON4 OFF TO CON2 ON TO CON1 Fig.3: here’s how to make the connections to the Altronics UHF remote PCB. The red and black leads shown are all part of the original wiring. The timer PCB is mounted on spacers on the rear of the front panel and is secured using eight M3 x 6mm machine screws. +12V TO CON4 ON CONTACTS: TO CON1 OFF CONTACTS: TO CON2 0V TO CON4 is almost certainly fully functional and it can be installed in a case, along with the remote’s PCB module. If it doesn’t work, go back over the PCB and check carefully for incorrect component values, incorrectly orientated parts and missed solder joints. Case installation Fig.4: the wiring connections to the Jaycar UHF remote. You will need to scrape away the solder masking from some of the tracks before soldering the leads. their flat sides orientated as shown and must be pushed all the way down before soldering their pins. The PCB assembly can now be completed by installing CON1-CON5. These polarised 2-way headers are installed on the rear of the PCB with their plastic tabs orientated as shown in the bottom diagram of Fig.2. Wiring the header sockets The header sockets are wired by crimping the wires into the crimp lugs and then pushing them into the socket shell. These wires can all initially be about 100mm long and you will need to use red and black leads for CON3CON5 as shown. The leads for CON1 & CON2 run to the ON & OFF switches on the remote PCB, so their polarity is unimportant. Test & adjustment Before applying power, make sure that IC1 is out of its socket and that 72  Silicon Chip all polarised parts are correctly orientated. That done, apply 12V DC to CON3 and use a DMM to check the supply between pins 14 & 5 of IC1’s socket. This should be somewhere between 4.75V and 5.25V. If this is correct, switch off, install IC1 (notch towards D5) and reapply power. The LCD should now show characters. Adjust VR1 for best contrast, then switch the backlighting on by pressing the backlight button (S10). Check that brightness can be adjusted by holding S10 down (the adjustment direction changes each time you press S10). Now press the On button (S8). A click from the ON relay should immediately be heard and the top line of the LCD should display “ON”. Similarly, pressing the Off button should briefly turn the OFF relay on and cause “OFF” to be displayed on the bottom line of the LCD. If the unit passes these tests, then it The PCB can be installed either in a UB1 plastic utility case (158 x 95 x 53mm) or in a sealed polycarbonate case with a clear lid (115 x 90 x 55mm). A front panel PCB coded 19112142 and measuring 157 x 94mm can be used with the UB1 box. This PCB replaces the plastic lid and comes with all holes drilled and screen-printed lettering. It’s available from the SILICON CHIP PartShop, as is the main PCB. Alternatively, a label measuring 144 x 84mm can be used with the existing lid on the UB1 box. A front panel label measuring 103 x 78mm is also available for the polycarbonate box. These labels can be downloaded in PDF format from the SILICON CHIP website and printed out. You will need to print out two copies – one onto plain paper for use as a drilling template and another onto photo paper to use as the front-panel label. The labels show the screwmounting locations for the PCB on the lid, along with the switch locations. A rectangular cut-out for the LCD surround will also be required for the siliconchip.com.au Dataflex & Datapol Labels (1) For Dataflex labels, go to: www.blanklabels.com.au/index. php?main_page=product_ info&cPath=49_60&products_ id=335 (2) For Datapol labels go to: www. blanklabels.com.au/index. php?main_page=product_ info&cPath=49_55&products_ id=326 UB1 box but this isn’t necessary for the polycarbonate case with the clear lid. The PCB mounting holes should be drilled to 3mm, while the switch holes should be started using a pilot drill and then carefully enlarged to 10mm using a tapered reamer. The rectangular display cut-out can be made in the UB1 box lid by first drilling a series of holes around the inside perimeter, then knocking out the centre piece and filing to a smooth finish. Once the holes have been drilled, the front-panel label can be affixed to the lid using a suitable glue or neutralcure silicone. Alternatively, you can print onto an A4-size synthetic “Dataflex” sticky label if you have an inkjet printer or onto a “Datapol” sticky label if you have a laser printer. This can then be trimmed to size and affixed to the base of the case using the label’s self-adhesive backing. Dataflex and Datapol labels are siliconchip.com.au Above: these two views show the inside of the unit with all wiring completed (Jaycar remote PCB used, no back-up battery fitted). Use neutral-cure silicone or hot melt glue to hold the wiring to the remote PCB in place. Features & Specifications • • • • • • • • Power: 12V DC at 30mA Current: 30mA with full backlighting; 3mA with backlighting off Battery backup current: typically 3mA On & Off IN: adjustable from 0h 0m to 99h 59m in 1-minute steps On & Off AT: adjustable from 0h 0m to 23h 59m (0h 0m shown as --:-– and timer is off) Real Time Clock: 24-hour format with hh:mm:ss Crystal tolerance compensation: ±99ppm Dimming: off to full brightness in 16 steps; 66.66kHz PWM (pulse width modulation). November 2014  73 Instructions For Using The Remote Switch Timer The very first time the Remote Switch Timer is powered up, the backlighting will be off and the timer will be in the ON IN and OFF IN Once Only mode (Fig.5). Two lines will be displayed on the LCD, with the top line showing ON IN“---:--” and the lower line OFF IN ---:--   The inverted commas in the first line show that the ON IN time can be changed using the Hours and Minutes Up/Down buttons. The dashes mean that the timer is off. Note that three dashes are allocated for the hours position and two for the minutes. This represents three digits for the hours and two for the minutes. The settings can be up to 255h 59m. Note that if you want an hour value above 127, it’s quicker to reach this by pressing the down button to count back from zero hours. Pressing the Next button (S6) moves the inverted commas to the second line. The LCD then shows OFF IN “---:--” and the hours and minutes for this setting can again be adjusted using the up and down buttons. Depending on the above setting, you also need to select whether the mains switch is initially on or off. That’s done by pressing the ON or OFF button (Fig.7). Pressing the Set/Start pushbutton (S5) then starts the timing, with the colon between the hours and minutes digits flashing and the inverted commas off. Pressing the Set/Start button again stops the timing or you can do this to change the ON IN or OFF IN values. Note that timing will not begin unless the colon is flashing. Changing the cycle To check which cycle you are running or to change the cycle, press the Cycle button (S7). The current cycle will be displayed and this will initially be ON/OFF IN Once Only. Other selections are ON/OFF IN Repeat, ON/OFF AT Repeat and ON/ OFF AT Once Only (Figs.8-10). You can just view the setting, by pressing the Cycle button for up to 10s. Pressing it for longer than 10s lets you move to the alternative settings. After 10s, the cycle indicator will be shown and the unit will count down from 10 to 0. When zero is reached, the cycle changes to the next selection. It’s just a matter of holding the Cycle button down until the required cycle is reached. The hours & minutes settings for the ON/OFF AT cycle are achieved in exactly the same manner as for the ON/OFF IN cycle, with the Next pushbutton again used to select the OFF AT timer. Adjust ppm correction Pressing the Next button after OFF AT has been selected brings up the “Adjust ppm” correction value on the top line and the real time clock on the bottom line (Fig.11). A right arrow shows which line can be changed using the Hours and Minutes buttons. As before, pressing the Next button cycles through the selections. The ppm setting is initially zero but can be changed using either the Hours or Minute buttons to ±99 maximum. A positive value speeds up the clock, while a negative value slows it down. A 1ppm change represents about 2.6s in 30 days or about 1s every 11.5 days. The 99ppm maximum adjustment corresponds to 256s in 30 days or about 8.53s per day. The real-time clock runs continuously and its time can only be changed in Set mode. The seconds are reset to zero each time the hours or minutes are changed, allowing the clock to be easily synchronised with another clock. Note that only the clock is shown in run mode, not the ppm crystal correction value. In practice, it’s all very straightforward and is far less complicated than it sounds. A few minutes spent playing with the buttons will familiarise you with the way it works. What’s remembered? If you don’t use the battery back-up, then the Remote Switch Timer will power off in a blackout or when you disconnect power. When power is restored, the timers will be at zero (showing dashes) and the clock will initially begin from zero (midnight). However, the cycle setting, backlight dimming level and crystal ppm correction value will all be restored to their values before power went off. By contrast, with battery back-up, the clock and timers will continue to run and their settings will not change. In addition, the last ON or OFF setting required for the remote mains socket will be remembered and re-sent after a 3s delay when power is restored. available from www.blanklabels.com. au and sample sheets are available on request to test in your printer – see panel. Once the label is in position, the Remote Switch Timer PCB can be attached to the rear of the lid using tapped spacers and M3 x 5mm ma74  Silicon Chip chine screws. M3 x 9mm spacers are used for the UB1 box, while M3 x 12mm spacers are used for the polycarbonate case so the LCD module sits inside the clear lid (this eliminates the need for a display cutout). Alternatively, if you are using a PCB front-panel with the UB1 box, it’s simply a matter of mounting the PCB on M3 x 9mm spacers. DC socket & battery holder An 8mm-diameter hole has to be drilled in the lefthand end of the case for the panel-mount DC socket. This can then be fitted in position siliconchip.com.au Fig.5: when first powered up, the unit is in ON IN and OFF IN Once Only mode. The inverted commas indicate that the ON IN time can be set using the Hours and Minutes buttons. Fig.6: the unit has been programmed here to turn on in 7.5 hours and off after 15 hours. Pressing the Set/Start button starts the timers. Fig.7: pressing the On or Off button sets the initial on/off state of the remote mains socket. Fig.8: different settings (or modes) are selected by pressing and holding down the Cycle button. ON/OFF-IN Repeat mode has been selected here. Fig.9: the ON/OFF-AT mode. Both Once Only and Repeat settings are available. Fig.10: the unit has been programmed here to turn on and off at set times. Fig.11: pressing the next button after OFF AT has been selected lets you adjust the clock and set the time. and the wiring leads connected (the other ends of these wires terminate in 2-way header socket CON3). Be sure to connect these leads to the correct terminals on the DC socket (check with a DMM if necessary). As stated, the back-up battery is optional. If you wish to use it, it’s just siliconchip.com.au a matter of connecting a 9V battery snap to CON5 and installing a 9V battery holder. Before soldering the battery snap leads, loop them through the adjacent strain relief holes. The holder can be secured to the base or to one side of the case using an M3 x 6mm machine screw and nut. Remote control PCB Before removing the remote’s PCB module, the remote control mains socket (either from Jaycar or Altronics; see parts list) should be set to operate as described in the instructions. This will familiarise you with the way the units works and allow you to set the channel number and test its operation. Once you’ve done that, the handheld remote can be disassembled. The Jaycar remote has one screw located beneath the battery cover and when removed, the two halves of the remote case can be cracked open along the sides with a screwdriver. By contrast, the Altronics remote has two screws under the battery compartment lid and removing these allows you to split the case. It’s then just a matter of removing the remote PCB and connecting the leads from CON1, CON2 and CON4. CON1 is wired across the ON contacts for the selected channel, CON2 across the OFF contacts and CON4 to the UHF remote’s supply rails. Figs.3 & 4 show the details. On the Jaycar remote, it will be necessary to scrape away the solder masking from the rear of the PCB before soldering the connections. Once all the wires are in place, fit a cable tie around the four switch wires to prevent them from pulling away from the PCB. It’s also a good idea to use neutral-cure silicone or hot melt glue to hold the wires in place. The remote PCB can now be mount­ ed on the base of the case. Both the Jaycar and Altronics remotes have two holes that can be used as mounting points, although the Jaycar unit’s holes will need to be enlarged to 3mm. In each case, the unit can be mounted (copper side up) on 9mm tapped spacers and secured using M3 x 5mm machine screws. Once it’s in place, plug the various leads into the sockets on the back of the timer PCB and fasten the lid down. That’s it – the unit is ready for use. The full instructions on driving it are SC in the accompanying panel. Helping to put you in Control LogBox RHT 32K Readings IP65 dual channel data logger with built-in temperature & humidity sensor. It can be easily programmed and configured via a handy IR-LINK 3 interface which connects to a USB port under Windows® software or PDA IrDA interface. Replacabe internal lithium (3.6V ½ AA) battery. SKU: LOG-005 Price:$159 +GST Any-Direction Microswitch Industrial microswitch with springy actuator triggers when the actuator is pushed or deflected in any direction. This makes it trivial to mount in a wide variety of situations. SKU: HES-204 Price:$12.95 +GST 10-Port USB Charging Hub 10 dedicated USB ports with a massive 60 W built in power in a compact design. 2 selectable types of charging current, 1 A or 2 A, 240 VAC powered. SKU: UHB-003 Price:$89.95 +GST USB Serial Stepper Controller Four axis stepper motor controller fitted with USB and RS-485 ports. Takes simple serial commands and produces ramped frequency profiles for stepper or servo motor control. Revised version can be 8 to 35 VDC powered and has analog inputs. SKU: KTA-290 Price:$79 +GST Power Multiplexer Carrier The Texas Instruments TPS2113A autoswitching power multiplexer allows you to switch seamlessly between two power sources of 2.8 V to 5.5 V, while blocking reverse current into either source & and the board also breaks out a USB Micro-B connector that can be used to supply one of the rails. It has an adjustable current up to 2 A. SKU: POL-2596 Price:$9.95 +GST Bluetooth 4.0 BLE Shield Bluetooth Low Energy (BLE) shield for Arduino based on the Nordic Semiconductor nRF8001. This shield lets your Arduino talk to your smartphone or other Bluetooth 4.0 equipped devices. 3.3 V or 5 V powered. SKU: SDA-001 Price:$34.95 +GST New MeanWell Slim Line Series MeanWell has recently announced the released of their highly anticipated new slim line series: EDR-120, NDR-120 & EDR-150. Only EDR-120 & NDR-120 offers standard output such as 12 VDC, 24 VDC and 48 VDC. EDR-150 is currently only available with 24 VDC output, but can be adjusted up to 156 W. These series will be available in late October. Contact us via phone, fax or e-mail to place your preorder. Price starting from $35 ea + GST. For OEM/Wholesale prices Contact Ocean Controls Ph: (03) 9782 5882 oceancontrols.com.au November 2014  75