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  1. Ylli

    Help with a 240v time delay relay setup

    Sounds to me that the OP simply needs a 'time out' circuit. Apply 240 VAC to the box, and it passes that 240 VAC through to the pump and starts a timer. If after 15 minutes, the 240 VAC is still present, then the timeout circuit shuts off its output and sounds an alarm. If the input 240 VAC...
  2. Ylli

    Question preservation electronic device and evaporation muriatic acid

    Protect parts that may be damaged by water (fewer than you might think), and then wash thoroughly with warm soapy water. A trip through the dish washer (set to air dry) can be quite effective.
  3. Ylli

    12 volts deep cycle battery

    When I worked on Gel Cells, they were always rated at the 20 hr rate. A 5 Ahr battery could deliver 0.25 amps for 20 hours. Any discharge rate higher than the 20 hr rate would lead to a reduced capacity.
  4. Ylli

    Diode Questions- Attempt at Vintage Turntable Resurrection

    The Zener is a 1N5232B. Most likely, a 1N4148 will work fine as a replacement for the 1S2743.
  5. Ylli

    What happens if you put a BJT in a 12V AC circuit?

    The collector - base junction would rectify and a half wave rectified voltage would be seen at the base. The polarity of this rectified voltage would be such that the base - emitter junction would remain reverse biased. THis would assume the applied AC voltage did not exceed the Vcbo of the...
  6. Ylli

    Auto Shut Down denon 1713 AVR

    Too much digital intrusion into what is an intrinsically analog device - a tuner/linear amplifier.
  7. Ylli

    Bose wave audio System

    Elektrotanya.com has some Bose Wave schematics.
  8. Ylli

    Newbie question...

    Wire wrapping without solder using stranded wire is quite common. The wire is tinned first so that the wrapping can create that gas-tight connection. When I have to unwrap one of these I usually re-wrap as neatly as possible - often shortening the stripped length of the wire, and then adding...
  9. Ylli

    Help me in calculating base resistance for transistor

    Edd's modifications are good ones. I'd just like to add my suggestion that you add 0.1 uF bypass capacitors on the power pins to ground at each IC - shortest possible leads.
  10. Ylli

    Trying to Fix Bluetooth Speaker, please help

    How about you tell us the make and model?
  11. Ylli

    Voltage converter for Samsung Ru8000 TV

    No I meant transmission standards. Historically, the US used NTSC, and Europe used SECAM. Don't know where are are from, and exactly what has become more or less compatible with the switch to digital, but it is something you might want to research.
  12. Ylli

    Voltage converter for Samsung Ru8000 TV

    Are you sure you are not going to have problems with signal source compatibilities?
  13. Ylli

    JVC RX-450 receiver has high impedance outputs

    Glad you found the issue. Many amps do not like loads heavier than 8 ohms. So when you switch in both speaker 1 and speaker 2, the speakers are connected in series instead of parallel. If you select speaker 2 and there is no speaker 2, then no complete circuit and no sound..
  14. Ylli

    JVC RX-450 receiver has high impedance outputs

    Is the 14 volts unloaded an ac voltage (audio) or is it a DC voltage (offset)? When you power on the unit, do you hear the protection relay click after a few seconds?
  15. Ylli

    Marantz SM500DC - defective

    Powered on, but not working - defective.
  16. Ylli

    Marantz SM500DC - defective

    My suspicion is that somehow you are loosing the +44 volts that comes from the load end (left side on the schematic) of R747. This +44 volts should show up at the top end of R731, R729, R711 and R709. When the unit is *not* working, please measure the voltage on the emitter of Q711.
  17. Ylli

    Marantz SM500DC - defective

    There is no way a defect in that relay could have caused the output offset voltage of one channel to be at -42 V. I suspect that the +44 volts that you measured on the load end of R747 wasn't there until you probed it. Look very carefully at the solder around the leads of R747 and reflow if...
  18. Ylli

    Marantz SM500DC - defective

    OK, let's back up a stage on the power amp and look at the voltages on Q711, Q715, and Q703, emitter , base, and collector.
  19. Ylli

    Marantz SM500DC - defective

    OK, right resistor/left channel :) Please measure the voltage on both ends of R747.
  20. Ylli

    Marantz SM500DC - defective

    On the lamps, it sounds like you just have a bunch burned out. The relay normally would not look like this, but: is your main problem. You said you checked the output transistors, did you check for collector-emitter shorts? We will need to make some voltage measurements on the right power...
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