| JAZZ2250 |
| Attached is a diagram of DIY speaker selector that I'm thinking to make before the end of this year. Though only 3 pairs of speakers are drwan in the diagram right now, it will actually be 7 pairs of speakers. So far, it's a simple relay circuit. Any kind of comment would be appreciated. Thanks. |
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| JAZZ2250 |
The following is parts list:
Relay:
Miniature enclosed power relay. 12 Vdc, 416 Ohm coil. Pc Pins.SPDT contacts rated 12 Amps @ 277 Vac, 16 Amps @ 250 Vac.
7 Position Rotary Switch:
Miniature single-pole, 7-position rotary switch with 1/8" diameter x 0.22" long shaft. 0.25" diameter 0.27" long threaded bushing. 0.6" diameter x 0.68" long body. Gold-plated solder terminals.
Power supply:
Input: 115 / 230 VacOutputs: 5 Vdc @ 0.7A and 12 Vdc @ 1.3A6.75" x 3.75" x 1.1." 9" wire leads with Molex-type connectors for output. 115/230 V selector slide switch.
These are pretty much I can think of now. Please feel free to add comment. Thanks. |
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| JAZZ2250 |
| Finished prototype testing, and seems to work fine. A PCB is made for relay board. Time to drill holes on PCB, now. Small modification is a change to 6-chn from 7-chn. So far, so good. |
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| redrumjoe666 |
It looks like your circuit is what's called "break before make". To cut to the chase, using this circuit will blow out your amplifier. Going from seeing infinite impedance to almost nothing will cause a feedback spike that causes the output stage to turn on to damaging levels. Its the same thing as if you shorted the output.
I hope you read this before you try it:att'n:
-Joe E. Baby |
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| JAZZ2250 |
Well... I haven't noticed that there was a reply. Fortunately, I haven't tried this project. Well... It would be correct to say that I haven't finished the whole project. Everything was assembled on PCBs, but not as a whole.
So, how could I avoid/reduce the feedback spikes? Does this also happen in solid state amplifiers? Could anybody let me know? Thanks. |
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| redrumjoe666 |
They make switches that are called make before break, designed especially with your application in mind. You should be able to find some on the web.
-Joe |
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| megajocke |
| You should use flyback diodes or those LEDs will eventually be zapped by the flyback pulse. I don't think break-before-make will be a problem with solid-state amps, but tube amps might not be too happy about an open output. |
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| redrumjoe666 |
| I've heard of solid-state amps not being very happy about break-before-make, not just with cheap ones either. |
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| JOE DIRT® |
I think the circuit will work but I think you should make sure the Amp is off when changing between speakers also Diodes across the coils is a definate must.
Cheers!!The DIRT® |
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| Rudy |
| quote: | Originally posted by redrumjoe666
It looks like your circuit is what's called "break before make". To cut to the chase, using this circuit will blow out your amplifier. Going from seeing infinite impedance to almost nothing will cause a feedback spike that causes the output stage to turn on to damaging levels. Its the same thing as if you shorted the output.
I hope you read this before you try it:att'n:
-Joe E. Baby |
isn't this the way all relay based delay circuits in solid state amps work :eek:
greetz Rudy |
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| redrumjoe666 |
| The relay is not going to be hooked up the same way, unless they add a dummy load to compensate. |
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