Search results

Search Forums New Posts
  1. Alec_t

    Op Amp with a/c output

    @ Harald Kapp Did you omit a link in post #46?
  2. Alec_t

    Op Amp with a/c output

    Although adding the 1k series resistor as mentioned above would avert the risk, it would also prevent the circuit doing what you want if the PCM has a low resistance input and is intended for a high-side switching Hall sensor. Unfortunately, the input characteristics of your PCM are a mystery :(.
  3. Alec_t

    MFOS VCO fault

    Ok. Now put the black probe on pin 3 and the red probe on +12V. With a 10k (or thereabouts) resistor connected temporarily between the two probes, what is the voltage reading?
  4. Alec_t

    Op Amp with a/c output

    The circuit I posted was designed in connection with a different thread (concerned with emulating a high-side Hall sensor) and for an ECU having a pull-down input resistance of around 100 Ohms. If your PCM doesn't have such an input arrangement then the circuit might not do what you want. Also...
  5. Alec_t

    Low voltage cut in/cut out

    :confused: You said (post #1) that the signal is 2.5V dropping to 2V.
  6. Alec_t

    Automated Water Mister (closed circuit soleniod switched off)

    Do you mean 0.6 AMPS?
  7. Alec_t

    Op Amp with a/c output

    In that case, I think this circuit could work : When Q1 switches on, C2 acts as a bootstrap to keep the opamp supply up.
  8. Alec_t

    Op Amp with a/c output

    Sorry to bang on, but I'm still having a problem understanding the logic behind this. Correct me if/where I'm wrong : 1) If the ISS sensor output is only 1.5VAC at idle, it (or its connection) is faulty. 2) If you build a circuit which has output pulses whose negative-going excursions go at...
  9. Alec_t

    MFOS VCO fault

    The way an opamp works in that voltage-follower configuration means that all of pins1,2,3 should be at the same potential (in theory). To check for an actual short, disconnect 1 and 2, temporarily ground 2, then measure the voltage at 3 (with the VCO powered on). It should be non-zero.
  10. Alec_t

    4-20mA splitter

    Did you see my post #2 edit? Here's a suggested circuit :- Note: emitter resistors R2 and R4 must have the same value as sense resistor R1.
  11. Alec_t

    Transmission Line Z0 error in LTSpice

    Welcome to EP! There's a syntax error in your nmos model statement.
  12. Alec_t

    4-20mA splitter

    Will the two slave loops have independent power supplies, or will all three loops share the 24V supply? Edit: An advantage of a current loop is that several devices can share it. So why do you wish to replicate the loop?
  13. Alec_t

    N-Channel Mosfet switch

    Where did you have the meter probes? The FET source is not grounded.
  14. Alec_t

    Electronic kart

    So you plan to use a battery-powered 12V to 220V inverter. That still means you would have a motor powered at a lethal 220v. Not recommended where children are concerned. They're inquisitive by nature and could easily poke fingers where they shouldn't.
  15. Alec_t

    Volt diff detection / comparator?

    Perhaps you could base the INT generator on a simple long-tail pair, something like this ;- C and D could generate INTs directly if you have two INT-capable negative -triggered Schmitt trigger inputs on the MCU.
  16. Alec_t

    Op Amp with a/c output

    Do they only do a visual test in the US? In Europe the test involves exhaust gas analysis at different rpms, so the error light would promptly come on again and the test would fail. A certain European car manufacturer fell foul of trying to cheat the emissions test.
  17. Alec_t

    Electronic kart

    That sounds highly dangerous :eek:. Children's electric vehicles are usually powered by a 6V or 12V sealed battery, for safety's sake..
  18. Alec_t

    N-Channel Mosfet switch

    What is the battery voltage? Why are R4/5 such high values and why use both? There may not be enough current through the switch to 'wet' the contacts.
  19. Alec_t

    Low voltage cut in/cut out

    Then I don't see how the TS proposes to use all the trigger points : ["I plan on four or five temperature/voltage trigger points to manage noise and electrical usage"]
  20. Alec_t

    Latching relay for actuator use?

    Latching relays (other than the impulse type) come in two flavours: single coil or double coil. Be aware that a single coil type requires a pulse of one polarity to set it and a pulse of the opposite polarity to reset it. A double coil type requires a pulse of one polarity on one coil to set it...
Top