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  1. KrisBlueNZ

    What value of resistors do I need and a sanity check

    Yes, they're preset potentiometers, also called trimpots. You could use ten-turn ones but I don't think it's necessary. The values I've specified for ALL of the components in the emitter path are ESTIMATES. You need to select the right values during testing. If you can afford it, you should get...
  2. KrisBlueNZ

    circuit that choose one input to output

    Or perhaps a CD4053. Your question is very vague.
  3. KrisBlueNZ

    What value of resistors do I need and a sanity check

    You can use a 9V battery if you reduce RB and RL. This will reduce the maximum voltage available from the circuit. This graph shows the effect of changing the battery voltage. This graph shows the electrode current on the vertical axis, and the "load resistance" (i.e. the resistance of the...
  4. KrisBlueNZ

    Programmable Interval Power Timer for Bubble Machine

    That's interesting. I wonder what the underlying reason was. Did you always feed positive and negative half-cycles through in pairs? I think you would probably have to. I don't know how a motor would respond to having every second cycle missing... my gut feeling is that it wouldn't like it. I...
  5. KrisBlueNZ

    What value of resistors do I need and a sanity check

    LOL! Take it easy :-) I hope the project works out for you.
  6. KrisBlueNZ

    Programmable Interval Power Timer for Bubble Machine

    Duke, I see. What you describe is not really a thermostat, it's a self-contained on-off cycler device that uses heat internally. I would like to use solid state switching at zero-crossings instead of contacts, but I will look into this option; thanks for the suggestion. Harald, I decided...
  7. KrisBlueNZ

    What value of resistors do I need and a sanity check

    Here is my suggsted schematic. It is based on a single transistor current source using a switchable current setting resistor in the emitter path. SW2 is a two-pole five-position rotary switch. The "A" pole enables one of five LEDs (LEDR, LEDS, LEDT, LEDU and LEDV) which indicate the current...
  8. KrisBlueNZ

    Programmable Interval Power Timer for Bubble Machine

    What I mean is that a thermostat will only cycle a heating appliance on and off if there is a thermal connection from the appliance to the thermostat. A thermostat in an independent box won't work, because there is no feedback from the heating element in the appliance to the thermostat. The...
  9. KrisBlueNZ

    Programmable Interval Power Timer for Bubble Machine

    Erm, the thermostat has to be able to detect the temperature of the appliance! If I just put it in an external box, it will never get hot and will never turn off!
  10. KrisBlueNZ

    Programmable Interval Power Timer for Bubble Machine

    Is that comment meant for me? You mean I could modify the toasted sandwich maker so it uses an adjustable thermostat instead of a fixed one?
  11. KrisBlueNZ

    Programmable Interval Power Timer for Bubble Machine

    My project log for my "notsohot" project. Please feel free to add comments and feedback. https://www.electronicspoint.com/notsohot-project-mains-power-cycler-heating-appliances-t251141.html#post1485706
  12. KrisBlueNZ

    Electron Tubes

    Hi jmichaelkel and welcome to the forums. It would be helpful to know where you are located.
  13. KrisBlueNZ

    Programmable Interval Power Timer for Bubble Machine

    Nice work Harald! I'm going to be starting on a similar project to cycle a kitchen appliance on and off using a cycle time around 10 seconds. We have a toastie pie maker that has a fixed thermosat, and I like to reuse it for reheating my health food (pies and sausage rolls :-) but it gets too...
  14. KrisBlueNZ

    What value of resistors do I need and a sanity check

    I have a few ideas for safety improvements too. I'll have a schematic up in a few days. I'm planning to base my design on your new circuit using the PNP current source, and use the rotary switch ideas from your newest version of the LM334Z-based circuit. Also I want to add a zener across the LED...
  15. KrisBlueNZ

    Help with Under Water Sony Remote?

    I guess I would prefer to use the purest I could get. I don't know the concentration of the stuff I've got.
  16. KrisBlueNZ

    What value of resistors do I need and a sanity check

    Are you waiting for one of us to draw it up? Dave, do you want to do it? Otherwise I will. BTW here are some high-efficiency/low-current red LEDs rated for usable operation at 1 mA that will be suitable for the "RED LED" position. #1...
  17. KrisBlueNZ

    spreading out the PWM on a PIC16F627a

    I assume you're intending to use one micro for all six plates? This could all be done pretty cleanly in firmware. You just need to be sure you have enough I/O and enough hardware to get a usable timing reference. I would start with a hardware definition, starting with I/O requirements. You'll...
  18. KrisBlueNZ

    What value of resistors do I need and a sanity check

    Yes, that circuit is good, and the description is thorough. Oh dear, I was hoping you weren't going to do that. I really recommend you try all your options for improving electrode contact before you start to increase the maximum voltage the circuit will deliver. That's a cute idea; I've...
  19. KrisBlueNZ

    Best type(s) of capacitor

    LOL :-) Thanks :-) No, unless you want to protect the components from accidentally reverse-connected batteries or supplies. That's the reason for connecting diodes ACROSS a power supply rail. It protects against reverse polarity, and if they're zener diodes, against excess voltage. Removing...
  20. KrisBlueNZ

    Help with Under Water Sony Remote?

    I forgot to mention. I've found a good idea for electronic equipment e.g. cellphones that are dropped in water is to dismantle the device as quickly as possible, remove any RF shields if possible, and brush isopropyl alcohol liberally over all components and both sides of all PCBs, and into ALL...
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