Search results

Search Forums New Posts
  1. (*steve*)

    Some info I read re UV exposure resist undercutting, with questions..

    Take a look at this: The interesting part runs from 14:30 to 18:20 Whilst etching is involved, it is not used to etch the full thickness of the copper.
  2. (*steve*)

    Some info I read re UV exposure resist undercutting, with questions..

    Another very important consideration for undercutting is the thickness of the copper layer. Using thin 1/2 oz copper will allow you to etch faster and this undercut proportionately less. Commercially made boards are not etched and don't suffer this problem.
  3. (*steve*)

    How do you post a circuit diagram

    Convert your postscript into a pdf, or better, to an image and upload that. The pdf may be better for complex things with lots of detail, but images can be viewed in line.
  4. (*steve*)

    Have seen many Youtube videos related to induction heaters but never for water?

    No, the amount of heat going into the water (Y) is much larger than the amount of electrical energy expended (X).
  5. (*steve*)

    Have seen many Youtube videos related to induction heaters but never for water?

    https://www.energymatters.com.au/solar-hot-water/solar-heat-pumps/ When I was in NZ last (in the middle of winter) people were starting to install heat pump space heaters. They certainly work with ambient temperatures < 0C. Of course it can. It's a heat pump. You're expending energy to...
  6. (*steve*)

    Have seen many Youtube videos related to induction heaters but never for water?

    Ok, if one defines efficiency by comparing the change in total thermal energy of the water with the electrical energy required to operate the device to cause that change, then a heat pump is more efficient, able to add Y kW of heat energy with an expenditure of X kW of electrical energy (and...
  7. (*steve*)

    Have seen many Youtube videos related to induction heaters but never for water?

    Well, actually, with heating water you CAN be more efficient. A heat pump can deliver more heat to the water than is consumed electrically.
  8. (*steve*)

    Have seen many Youtube videos related to induction heaters but never for water?

    Google "induction water heater" and you will find YouTube videos.
  9. (*steve*)

    I buy am/fm radio kit but something i dont understand

    Quod erat demonstrandum.
  10. (*steve*)

    Capacitor charging

    Included in the circuit resistance will be the internal resistance of your power supply. This internal resistance works a bit like a fixed resistance n series with a voltage source. The time constant (R x C) it the time taken for the capacitor to reach about 60% of the source voltage. After...
  11. (*steve*)

    I buy am/fm radio kit but something i dont understand

    Audioguru believes that unless something is perfect it has no value.
  12. (*steve*)

    Talking to my phone

    I don't have that much to say. Unless I hit my thumb with a hammer.
  13. (*steve*)

    Live Audience Response System

    In some respects wireless may be easier. I'd put an ESP8266 module inside a box with a battery and a few buttons. When you press a button it tries to connect to the network. if it fails to connect it backs off for a random time interval before trying again. When it does, it sends its unique...
  14. (*steve*)

    Bad Linksys router; how can I connect to its serial debug port?

    What is the voltage swing of this debug port? Is it the same (i.e. not less than) the voltage swing for another port which worked? If your logic analyser can decode rs232, does it get the same garbled characters?
  15. (*steve*)

    Hi everyone

    Welcome. Thanks for the donuts. I'll pass on the coffee at the moment though. Here are some Timtams. I trust you know what to do with them when you have a cup of coffee. :-)
  16. (*steve*)

    Live Audience Response System

    I was just in an audience that had to do this. The instructions started out with... "Get out your phone and download the app xxxx from your app store. When asked, put in the number yyyyy..." Worked like a charm. Everyone had their own touch screen device and the organiser didn't have to...
  17. (*steve*)

    PCB mounted transformer How to identify?

    Ok, but how do you know the bridge rectifier was working properly? I would have tested the bridge rectifier with the power off. I also assume that you were not holding any more than one probe when measuring these voltages.
  18. (*steve*)

    Talking to my phone

    Hi Matilda, do you want to go for a drink after work question I'll see hyphen it depends. Oh, sorry I phone maybe next week question Well, at least some of work. At least my phone doesn't want to converse with me (for now)
  19. (*steve*)

    Phantom powered preamp

    Hi @Marrie, the circuit you've come up with is very similar to those that are actually used. I posted a few previously, but here is a trivially simple example: It might not look too similar, but let's re-draw it... The microphone (V1 and Q3) in conjunction with R4 and R5 simply produces...
  20. (*steve*)

    1/4 inch mono jack 3 pins

    My rant wasn't directed at you, but rather at the confusing terminology. I'm pretty sure you got the "jack" part of the terminology correct (although I still had to verify it -- your pictures did that).
Top