Search results

  1. CDRIVE

    Turn on device when car speaker signal detected

    I suggest you read his first post again. He'll take the solution any way you give it to him. So why bust his balls? Just be civil and do what you're supposed to be here for.... Provide help! Chris If I sound pissed it's because I am!
  2. CDRIVE

    16 mm sound troubleshooting (no sound)

    This is my second try to paste the image. I hope it's successful. Chris Edit: It's too large.
  3. CDRIVE

    Transistor Power

    Personally I think our new member is not asking what the maximum power dissipation rating is but rather what it means. Or to be more precise when and where does maximum power dissipation occur as it relates to collector voltage and current. pidja105 take a look at this circuit and the plots it...
  4. CDRIVE

    Water detector with NE555

    Here's a link posted by another student. https://www.electronicspoint.com/threads/can-any-one-help-on-a-project-that-has-two-inputs-it-gives-an-output-based-on-the-inputs.282281/ He is the antithesis of you. I didn't check your calculations for accuracy but I did marvel at your effort. My...
  5. CDRIVE

    Extraction Automation Complete!

    That's not cheating. It's being practical. It's hard to beat or even resist those Chinese modules. China sells a plethora of electronics products targeted at electronics enthusiasts and DIY'rs. I'M A CHINA'S EBAY ADDICT!! You couldn't buy the individual components or even the bare PCB (alone)...
  6. CDRIVE

    Turn on device when car speaker signal detected

    Yes, that circuit should work but I would move R1. I think you'd be better off connecting one end to the base of Q1 and the other end to the junction of C1 and Cathode of D1. You can use a common 2N2222 NPN and a common 2N2907 PNP. Just about any small signal NPN & PNP will do the job. One note...
  7. CDRIVE

    Extraction Automation Complete!

    Very nice but I'm curious why the dust collector remains running for a full 30 seconds after the blast gate is closed? Chris
  8. CDRIVE

    Cut Constant Glow in LED

    Better yet provide us with links to the devices you're using. We will be able to make much better sense from the manufacturer or supplier's descriptions. Chris
  9. CDRIVE

    Measuring AC usage - aka, LOAD

    Curiosity is killing me. I live where furnaces don't exist for heating homes. Just about all our structures are electric (forced air over hot wire) heat. That said you'd be hard pressed to find a home that draws 80Amps! What kind of furnace is this? Chris
  10. CDRIVE

    555 on/off circuit for 5v motor (w/ schematic)

    Yes, that would be good practice but a 555 is hardly a discrete component. ;) Chris
  11. CDRIVE

    Water detector with NE555

    That's why I prefaced that statement with "I must be missing something". As it turns out, I was! I didn't notice that the 555 was being used as an astable osc. I thought the 555 was being used for a specific on time (output high) after it's triggered. I saw the "Buzzer" on the schematic and...
  12. CDRIVE

    Water detector with NE555

    Since Alec is not a novice at this I must assume I'm missing something. Alec why couldn't he just connect the LED cathode to the Output pin and the limiting resistor to Vcc? After all the output pin sinks low when off. Chris
  13. CDRIVE

    555 on/off circuit for 5v motor (w/ schematic)

    This is an addendum to my last post. I just ran some DC Transfer curves for a 2N2222 with a load current of 120mA and something isn't adding up at your end. The only explanation that I can extrapolate from this is that your power source is not stable. What exactly is supplying your 7V, which is...
  14. CDRIVE

    555 on/off circuit for 5v motor (w/ schematic)

    p1ne, please elaborate on the Diode voltage drop you're referring to. The protection diode across the motor doesn't contribute to voltage drop. The only other diodes in the Alec's circuit are used for charge and discharge path for the timing cap. They have no effect on voltage drop in the motor...
  15. CDRIVE

    555 on/off circuit for 5v motor (w/ schematic)

    Do you remember this post from Bob? His last sentence is what we strive for when using a transistor as a switch. If your supply is 7V and the motor is dropping 5.5V when Q1 is on then Q1 not saturated. Q1 is dropping 1.5V which is 7.5 times higher than 0.2V. Since you're concerned about not...
  16. CDRIVE

    555 on/off circuit for 5v motor (w/ schematic)

    I have no idea what you said but I think it translates to connecting the collector directly the Vcc and emitter to GND. If so there's no mystery why the transistor popped. Glad it's working now but it's time to trim the base resistor to a proper value for good saturation. The base resistor...
  17. CDRIVE

    555 on/off circuit for 5v motor (w/ schematic)

    It should have been wired like this and omitting the Diode is an invitation to back EMF destruction of the transistor. Chris
  18. CDRIVE

    NPN circuit isn't switching after power change

    OK, now that we've defined the transistor type has anyone been able to read the specs on his sensor? Most sensors provide an open collector output that pulls low when triggered. If that's the case I don't think he needs the transistor at all. MrJymm, please post the manufacturer and part...
  19. CDRIVE

    Circuit Which Turn On The Light As A Response To A Specific Sound Sequence ?

    What's going to generate the beep sound? Chris
  20. CDRIVE

    555 on/off circuit for 5v motor (w/ schematic)

    It goes to GND as you have it but the + pin shouldn't be connected to the +5V rail. Chris
View older results
Top