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Recent content by Al Chemist

  1. A

    Help Increasing Time Delay on Motion Sensing Camera

    I figure the only change is C2 = 47µF in the second version? If you mean one wakeup pulse cycle.. ie Standby 3v.. 0v Wakeup Pulse.. 3v Standby.. 0v Record Pulse, then that will do, but there may be several recording sessions each one requiring a wakeup cycle. I shall get the parts and...
  2. A

    Help Increasing Time Delay on Motion Sensing Camera

    Looking good, my main concern was the 5mS pulses in the waveform shown maybe too short. I've tried to test this by manually "dabbing" connections to replicate a trigger by removing the output (Collector Q3 NPN transistor) in this sequence ON OFF ON OFF as fast as I could and that did...
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    Help Increasing Time Delay on Motion Sensing Camera

    Sounds about right BrownOut, the "wake up" pulse being down to zero volts then back up to 3.8v then back down to zero volts from the timer signal. I'm not sure how long those pulses should be, but mS sounds about right. Is there a widget that does that? ;)
  4. A

    Help Increasing Time Delay on Motion Sensing Camera

    Never say die!!!! I don't think putting a manual switch on the LCD display is going to work, I did take the DVR apart but as you can see from the photos, it's the usual ribbon/tape connection to the display, which I would destroy if I put a soldering iron anywhere near it!! I think there...
  5. A

    Help Increasing Time Delay on Motion Sensing Camera

    Inscrutible Chinese design baffles me So was I.. BUT............. NO I've been thwarted!!! :mad: While I was testing it I noticed an inconsistancy in the commence recording cycle, for some reason best known to the manufacturer/designers if the LCD display goes into standby, then it...
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    Help Increasing Time Delay on Motion Sensing Camera

    It works!!! No need... the latest circuit does work.... YAY!!!!!! :D I used two 555 timers but it works brilliantly.. very many thanks and thanks for your time and patience. Let me know if you received my PM on possibly making a few of these units Brownout for $$$$.. the PM doesn't...
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    Help Increasing Time Delay on Motion Sensing Camera

    The 556 always struck me as the more elegant solution to this problem, I hope it works. I'm a keen advocate of live and learn, so no problem for me :) Output Capacity? is that amps or watts or another measure? I doubt if I'll be able to borrow a scope, but I can measure down to 200µA on...
  8. A

    Help Increasing Time Delay on Motion Sensing Camera

    I figured it was nearly there after the early success. :( Is the problem with the last circuit anything do with the resitance on the output, ie 39KΩ up to 5MΩ (+39KΩ)? I haven't changed that part of the circuit at all. I'm thinking it might need something like a relay, e.g. no voltage...
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    Help Increasing Time Delay on Motion Sensing Camera

    Sorry if the 12.2kΩ between Pin2 and Pin8 was intended, all OK. I'm more familiar with higher voltages in AC so it seemed like a low resistance to me ;) Also, my mistake, I did mean removing the R1 resistor. I think we only have 3 input/output voltages to consider, and in two states, no...
  10. A

    Help Increasing Time Delay on Motion Sensing Camera

    It doesn't appear to be working, it just sits there not seeing motion, which translates as there is a voltage permanantly on terminal 2 on the T555 I would guess. Which if you look at the circuit, R1 (2.2kΩ) sits between terminal 8 (Vcc) and terminal 2 via R4 (10kΩ), which basically means...
  11. A

    Help Increasing Time Delay on Motion Sensing Camera

    Thanks for the reply Brownout, it didn't email notify again, I'll give that a whirl asap. Thanks again.
  12. A

    Help Increasing Time Delay on Motion Sensing Camera

    Famous last words eh :D Hopefully we won't need to add it to the list... add it to the list **broken link removed** ;)
  13. A

    Help Increasing Time Delay on Motion Sensing Camera

    All OK and checked ie.. Q2 Base resistor R4 = 10kΩ then connects to 555 Pin 2 Q2 Emitter resistor R3 = 1kΩ then connects to 555 Pin 8 555 pin2 to Gnd = 3.14v no motion, 2.55v with motion Q2 Base to Gnd = 3.10v no motion, 2.62v with motion Slight volt drop due to the R4 resistor I'd...
  14. A

    Help Increasing Time Delay on Motion Sensing Camera

    I may have spotted the problem.. Cell voltage = 3.79V & 4.2V (has 3 contacts) VCC across GND & 555 pin 8 = 3.79V VCC across C1 = 0.07V 0V at Q1 base = 0.24V no motion 0.44V with motion VCC at Q2 base = 3.1V no motion 2.55V with motion 2.55v should be the trigger voltage, ie 0v...
  15. A

    Help Increasing Time Delay on Motion Sensing Camera

    I tried disconnecting pin 7 but it makes no difference at all. from bootup, the DVR goes into awaiting motion mode, and with no motion after about 4 seconds it starts recording and doesn't stop recording regardless of whether there is motion or what value the variable resistor is set to...
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