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  1. KrisBlueNZ

    Driving an SSR input from a DC power adapter

    OK, the D2410 has a current regulator in its input path, so it draws about 10 mA at any input voltage from 5V to 30V. At 3V it draws a bit less than 10 mA but it is still guaranteed to operate. So a power supply rated for 3V and 200 mA will be fine.
  2. KrisBlueNZ

    Driving an SSR input from a DC power adapter

    Hello and welcome to Electronics Point :-) I have moved your question to a new thread and sent you a PM so you will be able to find it. Yes, you can drive the SSR from a supply rated at 3V and 200 mA. The 200 mA part of the adapter's specification is the maximum current that it's designed...
  3. KrisBlueNZ

    Adjustable controller

    I don't think that would be workable unless (a) the appliances could be grouped into two sets that had roughly the same power consumption, AND (b) the appliances either drew the same amount of current all the time, or switched on and off in unison. Since these are heating loads, controlled...
  4. KrisBlueNZ

    yamaha receiver wont power on

    Yes that's a real bummer. You could try advertising that you want to buy a faulty unit of the same model number, but the chance of finding one would be slimmer than a runway model :-) You too my friend :-)
  5. KrisBlueNZ

    PIC polled on RS485 link

    You CAN insert resistors and/or diodes in the data path so you can see which device is transmitting and when. You could also try changing the VCC voltage of one of the transceivers. You can also combine your device's transmit enable signal with the data using two resistors - one resistor, say...
  6. KrisBlueNZ

    Adjustable controller

    I had a similar idea to Steve's. Detect when the heavy load's thermostat turns ON and kill the lower priority loads during that time. But I agree with Steve that it's probably not a suitable project for a beginner. One way to make it a bit tidier would be to modify the inside of the heavy load...
  7. KrisBlueNZ

    Simple alarm circuit help!!

    There are quite a few visible errors in your breadboard layout. You have pin 2 of the first 555 connected to the wrong side of the pushbutton. It is shorted to the 0V rail. This will keep the monostable permanently triggered; the button has no effect. The wire from pin 3 of the first 555...
  8. KrisBlueNZ

    PIC16F84A - Confusing output

    The errors I can see are: 1. The value in W when you call TABLE must be 0~3, not 1~4, because when the addwf PCL operation is executed, the program counter has already advanced to the first retlw instruction in the table. If you want to execute that instruction, you need to add 0 to the program...
  9. KrisBlueNZ

    Lab supply

    Right, I'm not surprised that the pads lifted off after four removals of the component! You have a decoupling capacitor, but it's not very close to the 4013 and it's connected through thin (inductive) tracks. I think it's worth trying a cap straight across the pins.
  10. KrisBlueNZ

    yamaha receiver wont power on

    OK, you've obviously investigated this pretty thoroughly. What's the story with pin 29, PSM (power save mode)? It's shown as high on the schematic, and it connects to a jumper to 0V. I guess the jumper is not fitted? If you touch the pin you see a square wave on the scope? Is it at mains...
  11. KrisBlueNZ

    Lab supply

    No, the reverse polarity protection circuit is OK. Here's how it works. When the battery is connected the right way round, current flows through Q2's body diode and powers up the circuit connected to its source. The gate is pulled negative by R3 and Q2 conducts, eliminating the voltage drop of...
  12. KrisBlueNZ

    Lab supply

    OK cool. You could also try connecting a 0.1 µF ceramic or multi-layer ceramic capacitor directly from pin 14 to pin 7 with the leads cut as short as possible.
  13. KrisBlueNZ

    Lab supply

    Interesting. I think it's possible that the TI part has a Schmitt trigger on the clock input. The data sheet doesn't show one; it shows a standard gate, but it's a very old data sheet (a scan, says it was acquired from Harris) and it would be possible to add a Schmitt trigger and still comply...
  14. KrisBlueNZ

    Robot parts

    I Googled robotics parts. Each of the first three hits has at least some of the things you want.
  15. KrisBlueNZ

    so..... I'm a new Dad!! :)

    Congratulations donkey! Is that like saying "You can pick your friends, and you can pick your nose, but you can't pick your friend's nose"? :-)
  16. KrisBlueNZ

    Old stereo amplifier, right channel gives weak signal and keeps disappearing

    Your description of touching a point in the circuit and getting a boom and "waking up" the circuit sounds like something I've seen a few times, due to a faulty transistor downstream of the point you touched. It's also possible that shaking or banging it could also cause a faulty transistor to...
  17. KrisBlueNZ

    Lab supply

    Hmm, that's strange. Perhaps the second flip-flop is clocking again on the falling edge of its clock input because of some noise or poorly defined voltage change. Try this. Lift pin 9 and tack a 10k resistor between the lifted IC pin and pin 7. Press and hold the pin onto the pad, power up the...
  18. KrisBlueNZ

    yamaha receiver wont power on

    Hi there and welcome to Electronics Point. Based on your comments, I guess you've found the service manual. If not, you can download it from elektrotanya.com. That one has schematics only. You can also get the data sheet for the main MCU from...
  19. KrisBlueNZ

    10 stages of different gains, output voltage is momentarily 1 volt

    We need to see a schematic diagram. Also please try to explain what the circuit is supposed to do.
  20. KrisBlueNZ

    Crystal accuracy

    I agree with BobK. The important parameter is the crystal error expressed as a percentage, or usually, in parts per million (ppm). The actual frequency is irrelevant, though it's true that a 32 kHz oscillator uses a lot less supply current than a 10 MHz one, for example. If you want detailed...
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