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  1. (*steve*)

    What does your workshop / workbench look like?

    Damn you're tidy :-)
  2. (*steve*)

    Load cell interference

    A low value gain resistor gives you a high gain, so a capacitor in parallel with the gain resistor would both increase gain for noise, but also potentially lead to instability.
  3. (*steve*)

    Can Power Supply Sink Current

    Very few power supplies can both sink and source current
  4. (*steve*)

    Load cell interference

    DONT do that. Read my edit. What is the value of your current gain setting resistor? If you can find a 1000uH choke, try adding that in series. If your gain is critical, remember that the choke will have a DC resistance.
  5. (*steve*)

    Load cell interference

    Shielding of your current may help, also reducing the gain at high frequencies may help. Try a capacitor across the resistor which sets the gain of the instrumentation amplifier. And don't leave the inputs disconnected. I'm not 100% sure that a capacitor across the gain setting resistor wont...
  6. (*steve*)

    Heathkit IP-18 Circuit Explanation Help

    The jfet Q1 supplies a current that is sufficient to turn on the Darlington pair of Q3/Q4 on sufficient to supply the maximum voltage at the maximum current. All the rest of the control circuitry is dedicated to shunting some of this away to maintain voltage regulation, any to override the...
  7. (*steve*)

    What does your workshop / workbench look like?

    My first workbench was a newspaper on the floor where I would sit and solder. I learned valuable lessons about standing on soldering irons. My first power supply was a 6V DC power supply for a slot car set. I learned what happens when you accidentally put a 6V power supply in parallel with a...
  8. (*steve*)

    What does your workshop / workbench look like?

    I would rarely use more than one scope at a time. However some of these scopes do things better than the others, so it can help to pick the right scope. Yeah, a DSA is sort of like a spectrum analyser. However the software allows you to do lots of interesting things. One of the simplest is...
  9. (*steve*)

    What does your workshop / workbench look like?

    Oh, I have a budget... And while it's not tiny, it's not as impressive as my test bench might indicate. I was thinking of buying a nice piece of test equipment, and when I looked at the prices for current equipment and decided I could buy a lot of old equipment for the same price. It also let...
  10. (*steve*)

    What does your workshop / workbench look like?

    I've probably posted mine before. I think this may be more recent. At the moment it's rather full of stuff, especially the parts to the left that you can't see on this photo. I'll clean it up some year...
  11. (*steve*)

    DIY automated power transfer switch

    If you can't withstand any delay the answer is to rectify and filter the mains then run an inverter from the DC. This arrangement generally has a battery and is called an online UPS. Once you have this you can take your time switching the AC source that is operating to the input of the UPS...
  12. (*steve*)

    Understanding Datasheets

    In a recent video, Dave Jones of eevblog goes through a datasheet showing you how to read it. Sure, it's not the component your interested in, but it may still be worth a look at.
  13. (*steve*)

    Help identifying a SOT23 part

    I've looked through my SMD codebooks and I can't find it.
  14. (*steve*)

    Increase In Output Pulse As Supply Increases In 555 Timer, Why?

    That's because The 555 cannot supply infinite current nor swing from rail to rail. You could use the output of the 555 to switch another transistor to drive the motor. Also, you need to put a reverse biased diode across the motor.
  15. (*steve*)

    Help identifying a SOT23 part

    It could also be a voltage detector chip, but they're more common on the reset pin of a microcontroller.
  16. (*steve*)

    Need to drain off curent.

    Your power supply operates in a single quadrant, that is, it can regulate when it is supplying a positive voltage and a positive current. This is fine when the lift is going up. When the lift is going down, the motors are being driven by the load, and the power supply sees a positive voltage...
  17. (*steve*)

    Increase In Output Pulse As Supply Increases In 555 Timer, Why?

    You probably want a 0.1uF 50V capacitor across the motor, and a 100uF across the 555.
  18. (*steve*)

    Increase In Output Pulse As Supply Increases In 555 Timer, Why?

    Two, one across the motor, one across the power supply pins of the 555
  19. (*steve*)

    Drive A 5w Led

    Have you read the resource on LEDs?
  20. (*steve*)

    Help me !

    Google for "Arduino hc05" There are plenty of tutorials. You don't need any resistors.
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