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  1. Tha fios agaibh

    Wiring Diagram For A Vox Pathfinder

    http://schems.com/bmampscom/vox/Vox_Pathfinder%20V1011%20Service%20Manual.pdf
  2. Tha fios agaibh

    Help with LED install...

    The dim first flash is because the flashing circuit needs to charge up during initial power up, and it discharges when not being used for a while. I'm not sure you can do anything about that unless you want to change or modify the flashing circuit. I say the fuse is very important. If you were...
  3. Tha fios agaibh

    CB/ballast on a OTTlite

    Its usually not practical to repair a ballast. Even if you find the bad parts, finding the replacements will be a challenge. Your better off just replacing it with one that matches the lamp type and wattage (don't worry about fixture number). You might be able to buy something like this...
  4. Tha fios agaibh

    garage door opener

    The sears door photo sensors I'm familiar with use a pulsed 6 volt DC signal that shows up on a digital meter as about 5v. If the beam us broken or misaligned it changes to a steady 6 volts to notify control board. Before bying another, You could try swapping the sensors or the boards and see if...
  5. Tha fios agaibh

    Unknown capacitor.

    Yes Sir, That's the path. Ok, I popped in a new zener a few minutes after getting my hands on it and the Punch machine is working fine. Yes, I thought about bench testing to find out the current required but I was curious how it's calculated form using the datasheet. Alas, I have a lot to...
  6. Tha fios agaibh

    Unknown capacitor.

    Thank you @kellys_eye, that does makes sense. Datasheets usually make my eyes glaze over like trying to read the fine print of a financial prospectus. Now that you've pointed my nose in the right direction I have a much better understanding of what (at least that chart) it means.
  7. Tha fios agaibh

    Unknown capacitor.

    @Harald Kapp: I realize the principles are the same, but is this opto-interrupter (photo switch) essentially the same as a opto coupler? I see nothing in the LTH-301-05 datasheet...
  8. Tha fios agaibh

    Unknown capacitor.

    @kellys_eye: I agree that 3.3k is not a problem and your advice that 4ma is sufficient. I am just trying to understand the datasheet minimum requirements for the PI. Particularly the ir led input. Data sheet states maximum values, but how do you know minimum values?
  9. Tha fios agaibh

    Unknown capacitor.

    @73's de Edd: Excellent observations all spot on except the 22uf + does go to transistor side with only one leg (what your illustration shows as collector) I think its the base. I'm not worried about plotting out the exact circuit at this point but its fun to know how stuff works...
  10. Tha fios agaibh

    Unknown capacitor.

    I'm trying to understand the datasheet, not just fix it. The main question I'm asking is; "what is required to sufficiently turn on the led to the point where the photo transistor sees it?" Even current in the microamp range will likely produce some photons of light but probably not enough...
  11. Tha fios agaibh

    Unknown capacitor.

    A crude sketch drawn without knowing the itty bitty transistor pinouts, in case anyone's interested. Waiting for postman to bring me a zener.
  12. Tha fios agaibh

    Unknown capacitor.

    Mr. 73's de Edd,( I would just call you Mr.Edd but it reminds me of a horse) Firstly, Thank you so much for taking the time to break this down. I always enjoy your witty and well illustrated responses. Forgive me if my reponces are out of order to points raised but I will get there. As far as...
  13. Tha fios agaibh

    Help needed identifying onboard fuse

    Often the amp and voltage ratings are marked on the metal ends. You may have to clean off the solder to find markings. Any clues on the board itself that may suggest what it may be rated?
  14. Tha fios agaibh

    garage door opener

    You likely have to program it (new board) to your remote control so it can communicate. Theres usually a learn button that you hold down while someone else clicks the remote. That way it will learn its code (frequency) What sensor are you referring to?
  15. Tha fios agaibh

    Unknown capacitor.

    To clarify, this is an optointerrupter, (photo switch) not an optoisolator. I hadn't considered ctr to be a factor on something like this with two separate devices separated with a big gap and presumably independent of each other. Besides, wouldn't a larger ctr require more input current than...
  16. Tha fios agaibh

    Unknown capacitor.

    Thanks but C4 is fine. It's probably good to go with a replacement zener, I just want to understand why its voltage is so seemingly low.
  17. Tha fios agaibh

    Unknown capacitor.

    Sorry, I was able to read markings on the zener. I think its a BZX 85c15 which is a 15v. How does this make any sense? Only 4ma to power led?
  18. Tha fios agaibh

    Unknown capacitor.

    I don't see it but does this help? If supply was only 24v the current the led would see would be just under 7ma at the typical 1.2v forward voltage, correct? (given that it has a 3k3 current limiting resistor)
  19. Tha fios agaibh

    Unknown capacitor.

    No, the 3k3 is in series with cathode of led side. Then the Anode of led goes to the collector of transistor collector(switch side) and a smd transistor. The emitter (npn) has a 10k in series with it.
  20. Tha fios agaibh

    Unknown capacitor.

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