Search results

Search Forums New Posts
  1. CDRIVE

    The Ultimate Tube RIAA-Amplifier?

    Hi Roger. Could you please enlarge that photo?. I'd love a closer look at that! Chris
  2. CDRIVE

    BT150 Thyristor equivalent(BT151) has just exploded !!!

    You're quite welcome. That circuit (top one) is suitable for SCR's too. Chris
  3. CDRIVE

    Need help with a Power Failure Alarm Circuit

    It took a while to find this. I drew it for another member in the UK where the mains are 220VAC. Your circuit common will be 1/2 this voltage but still lethal. Note: Though I show a GND symbol on mains neutral it was done for the spice sim only. Mains Neutral is not considered earth ground...
  4. CDRIVE

    BT150 Thyristor equivalent(BT151) has just exploded !!!

    You can try this to test Triacs with a DMM. I show a push button switch but you could use a momentary jumper. ;) Chris EDIT: Diode/Continuity mode is not the same as the Rx (Ohms) ranges! EDIT2: This circuit is only suitable for small signal (logic type) thyristors. Please read mea...
  5. CDRIVE

    Convert V to mV

    What does Steve call it? Ah, I think it's "The Nubies Secret Circuit Circus" section! :D Chris
  6. CDRIVE

    The Ultimate Tube RIAA-Amplifier?

    I said I'd post this so here it is. Possibly inconclusive, as I don't know if space charge is accounted for in the pcode. Chris
  7. CDRIVE

    Need help with a Power Failure Alarm Circuit

    Yes Kris, OptoCouplers were discussed in this thread 8 months ago. It appears to have been ignored. I have mentioned this before but it's worth repeating. When a Bridge is directly connected to the mains the circuit can not be grounded. Doing so will short out a section of the bridge. On the...
  8. CDRIVE

    The Ultimate Tube RIAA-Amplifier?

    I must admit that all this information has me reeling. Regarding space charge bias, I can't sim it, or to be more precise my sims on a 12AX7 don't validate it. I swept the grid resistor from 0 to 100Meg but the plate current didn't so much as twitch. Regarding tubes that operated down to...
  9. CDRIVE

    The Ultimate Tube RIAA-Amplifier?

    Sorry, I misunderstood you. I took rp to mean the plate resistor. Chris
  10. CDRIVE

    Need help with a Power Failure Alarm Circuit

    How did ya know that we've been sitting in front of our PC's for the last 8 months waiting for your reply? :rolleyes: You seem hell bent on connecting this directly to the mains so I'm outa here. By the way, I realize that spice simulators like to see ground but if you tie that to the mains...
  11. CDRIVE

    Convert V to mV

    Bob, I don't think I ever saw the ASCII version but I did see the cartoon which made me laugh! Animated ASCII? Wow, that must have been a bunch of coding! Why the hell to some nubes constantly do this? I'm talking about mystery posts where the OP gives us info in dribs and drabs but never...
  12. CDRIVE

    BT150 Thyristor equivalent(BT151) has just exploded !!!

    Your welcome. As is it will test a Triac in only one direction. I'll draw up another print for you. You're confusing me. The BT150 is an SCR. Chris
  13. CDRIVE

    The Ultimate Tube RIAA-Amplifier?

    I ran some sims. I'll post them when I get back from a bike ride. Chris
  14. CDRIVE

    Convert V to mV

    So you want to setup a 10KM Laser Diode transmitter - receiver? I still don't see how your question relates. By the way, Lasers are "Line Of Sight" devices. Have you considered the following limitations? http://www.ringbell.co.uk/info/hdist.htm Chris
  15. CDRIVE

    Frequency meter

    Damn, I hope you don't take my title as most ancient. :D Chris
  16. CDRIVE

    Frequency meter

    Since it's only audio freq that you need have you considered a free software PC scope? It wouldn't surprise me if some of them have a digital readout too. ;) Chris
  17. CDRIVE

    BT150 Thyristor equivalent(BT151) has just exploded !!!

    If you want something more permanent you could put this together. Chris
  18. CDRIVE

    BT150 Thyristor equivalent(BT151) has just exploded !!!

    This is a logic level SCR so you can try this simple test. Place your DMM on Diode Check Connect the Red (+) probe to the Anode. Connect the Black (-) probe to the Cathode. Using a jumper short the Anode to the Gate momentarily. The SCR should fire and the meter should drop to near zero...
  19. CDRIVE

    BT150 Thyristor equivalent(BT151) has just exploded !!!

    This is the point where we usually request some clear photos of the device and PCB. ;) Chris
  20. CDRIVE

    The Ultimate Tube RIAA-Amplifier?

    Hi Roger. While your amp is not intended as a power amplifier are you certain it's not closer to Rp/2? Following the maximum power theorem I don't see how it could be 2Rp. Rp is the plate resistor, right? Chris
Top