Recent content by vajirkar

  1. vajirkar

    Latch does not work with transistor loaded

    Audioguru, Yeah... that's the rest of the circuit. Thanks for the techniques/precautions. About the complex "flip-flop" :) , I'd love to hear comments and critical and otherwise. How can I improve this? I would have just loved to avoid the mess by programming the microcontroller myself. I just...
  2. vajirkar

    Latch does not work with transistor loaded

    I tried to narrow down the problem and it seems to be related to length of the wires to the limit switches. I simulated the limit switches by a pair of jumpers on the board and the latching is much more reliable. So its possible that in rare circumstances the relay-switching noise does affect...
  3. vajirkar

    Latch does not work with transistor loaded

    I was thinking of adding an extra transistor driver between the AND gate output and the limit switch. Dunno if its going to help. - Sid
  4. vajirkar

    Latch does not work with transistor loaded

    I have a latch driving a transistor (indirectly through a few gates). The transistor is used to drive a relay that drives a 110V linear actuator motor. When the relay is not connected to the actuator motor, the latch works perfectly. A single button click is enough to set the latch, the reset...
  5. vajirkar

    fast switch-off for transistor switch

    Thanks for all the detailed info guys. I tried all the different techniques, but the main problem seems to be that sudden switching of the large inductive load isn't a great idea. All I actually needed was a way to stop the actuator motor, so I just added an extra button to switch off both...
  6. vajirkar

    fast switch-off for transistor switch

    Let me add that the load is a motor of a linear actuator. Could it be possible that its not good to suddenly change the direction of rotation for a motor (inductive) load? Maybe there is nothing wrong with the transistor switching circuit at all! - Sid
  7. vajirkar

    fast switch-off for transistor switch

    GPG.. yes that's exactly what I have done, and that's why I don't have spare contacts. For some reason I still see a spark. See the attached image. MP, you are probably right. I did have 100K and 1M there first I may have made a mistake in switching to 10K. I'll try using the 10K and 100K as...
  8. vajirkar

    pad2pad custom PCB manufacturers

    This may have been discussed here before, so apologies for any repetition. Has anyone used the services offered by www.pad2pad.com? The layout drawing tool seems nice, but how is their manufacturing and pricing? - Sid
  9. vajirkar

    fast switch-off for transistor switch

    Thanks, nice explanation audioguru. Thanks again for the suggestion. I'll give it shot over the weekend. - Sid
  10. vajirkar

    schematics for IR remote for tv/vcr/dvd

    kingratman, I was trying to build a IR receiver for a mini-project and in the process found a bunch of IR transmitter (remote control) circuits on the net. Just google for IR remote circuit, you will find tons of them. BTW if anyone is looking for a simple IR receiver check rentron.com...
  11. vajirkar

    fast switch-off for transistor switch

    GPG, I don't have any spare contacts on the relays. If I did, what did you have in mind? Just curious. Audioguru, I like that idea. Why is the diode at the emitter needed? The discharge will occur from the diode at the base, no? Thanks for your responses, Sid
  12. vajirkar

    fast switch-off for transistor switch

    Hi guys, I have a simple transistor switch driving a relay. See the first figure (without diode D1). I have two such transistors driving two relays. The relays switch a 110V load. Ideally only one relay should be switched on at a time, so only one transistor should be switched on. The driving...
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