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  1. duke37

    trying to regulate dc voltage

    You could try putting a silicon diode in series with the supply to the radio, this will drop a volt or so. Chose a 5A diode. There is no explanation of why the radio is so fussy, perhaps you have not peeked at the peaks!
  2. duke37

    current division in circuit

    Try using ohms law. With ideal components, in the first circuit, you have a 1V source and a zero ohm short. What is the current? Is this possible?
  3. duke37

    Help PILLER component

    These look to be a combination of capacitor and resistor, used to reduce spikes (snubbers). There will be six diodes somewhere to rectify the three phase. Have you checked these? You could replace with a capacitor in series with a resistor if you have sufficient room.
  4. duke37

    I just had a vision of the future of TV.

    But Laplace managed a transformation.
  5. duke37

    Wall Wart Question

    It looks as if the feedback is through the optical isolator. When Q1 on, it inhibits the oscillator (Q2)
  6. duke37

    Rectifier, what am I looking at here

    It is a single phase rectifier with four diodes and four connections. The two connections at the side come from the alternator. The case is connected to the bottom and the output connected to the top. The output connection is different from the other two. The heat dissipation will be the same...
  7. duke37

    Rectifier, what am I looking at here

    This looks like a three phase rectifier. It can be replaced with three diodes but waterproofing will be the main problem. There must be a fourth terminal and this could be the case. A circuit diagram would help. Mica was used to electricaly insulate diodes and transistors whilst allowing...
  8. duke37

    Light works with power supply not connected to PCB

    Strange results can occur with vehicle lights if there is a faulty earth. If there is no earth to the light cluster, then a low powered light can work by supplying an earth through a more powerful light. In the case of a car, a side light can go out when the brake light comes on. In the case of...
  9. duke37

    Single Flashing LED circuit

    The long led leg should go towards the + end of the battery. The short leg should go towards the - end of the battery. Arn't there two yellow bands on the resistor?
  10. duke37

    PIR switching relay problem

    If the PIR can switch 2000W resistive, then it should not mind a small relay but to be sure, put a small light bulb across the relay to absorb any voltage spikes. I do not understand why the relay is sticking in unless there is some current leakage in the PIR. A small load (the light) may...
  11. duke37

    Latching circuit problem

    Look at RS 291-9704 Does it have to be a reed relay?
  12. duke37

    Latching circuit problem

    Reed switches are available with NO and NC contacts (Maplin etc). One of each would do your job.
  13. duke37

    PIR switching relay problem

    Relay can stick in if there is sufficient remanent magnetic field. DC driven relays sometimes have a little screw to keep the pole pieces slightly apart to ameliorate this situation. This can wear after many operations and may need adjusting. I have never seen such a screw on an AC driven relay.
  14. duke37

    problem with digital multimeter

    Good work. Now that you know some characterisics of your battery, what nominal voltage would you use to describe it?
  15. duke37

    help needed with pulsing a latched realay

    More information woul be helpful (I am always saying that). One way would be to connect a capacitor to the relay contact so that a pulse is generated when the relay pulls in. Another capacitor connected to the back contact would give another pulse when the relay drops out. These pulses could...
  16. duke37

    Inverter problems

    Show a circuit diagram of the inverter so that we can see what you have. If the voltage is reducing, is the power supply holding up?
  17. duke37

    pressure sensor switch PN5004

    The maximum output current is 250mA. What voltage and current does your solenoid need?
  18. duke37

    problem with digital multimeter

    No, what is more real is the voltage when the battery is supplying power. Did you try measuring the voltage when the battery is loaded with your 990 ohm resistor as I suggested earlier?
  19. duke37

    problem with digital multimeter

    Because a new AA battery will have a terminal voltage of 1.57V. Try an old one and see what you get then.
  20. duke37

    Heat Generation

    The humidity sensor as found by Steve seems the way to go but if you wish to make your own, then a flag in a slotted optical coupler would be the easiest. You will need to realise that the sensor, whatever it is will not respond instantly since time will be required for the moisture to...
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