Need Help About Speaker Relay!

tommy1 · 5th February 2010, 07:37 PM

Hello everyone,
Does the speaker relay turn on with out the output TRANSISTORS?

Thank you!

nigelwright7557 · 5th February 2010, 08:14 PM

The output transistors turn on before the relay does.

There is usually a couple of second delay from when teh amp is powered up until the output is connected to the speakers.

tommy1 · 08:54 PM

Thank you for relying.
What I mean was "can the relay kick on if the OUTPUT TRANSISTORS WERE TAKEN OUT OF THE CIRCUIT BOARD?"

Without the OUTPUT ...C: 33 Volts, Bass: 32 Volts, E: 0 Volts. When I put the OUTPUT back in the circuit board
then the Bass turns to be zero Volts ????

EchoWars · 6th February 2010, 12:17 PM

Depends on what the removal of the transistors does to the feedback loop. So the answer here is 'maybe'. A schematic of your amp would help.

maxpou · 6th February 2010, 02:14 PM

Hi Tommy1,
why do you removed the output transistors? Maxpou

5th element · 6th February 2010, 02:29 PM

If the relay control circuit is designed properly it will not turn them on if there is any appreciable DC on the output of the amplifier.

An amplifier without any output transistors might show one of the rail voltages on the output, this would stop the relays from closing.

On the other hand, if the output transistors had blown and the rail fuses blew as a result, then there might be no DC on the output and the relays will close. That is if the relays and control circuitry are not powered after the amplifiers rail fuses.

What is it that's gone wrong?

tommy1 · 6th February 2010, 04:58 PM

...ansewering to MAXPOU. I removed the output transistors for safety. However, the Amp is working execpt the relay does not kick on because of the IC C1237.
I got the audio output before the relay. So far, I have replace the UPC1237HA.

Thank you so much to all the friends in this forum !

kevvywevvywoo · 8th February 2010, 09:10 PM

what make and model amp is it?

tommy1 · 8th February 2010, 09:53 PM

The model # a-501 made by API

janneman · 8th February 2010, 10:06 PM

Quote:

Originally Posted by tommy1

...ansewering to MAXPOU. I removed the output transistors for safety. However, the Amp is working execpt the relay does not kick on because of the IC C1237.
I got the audio output before the relay. So far, I have replace the UPC1237HA.

Thank you so much to all the friends in this forum !

The UPC1237 will keep the relay open if there is a little DC on the output. Can you measure the output DC with no signal?

jd

5th February 2010, 07:37 PM	#1
tommy1 diyAudio Member Join Date: Jan 2010	Need Help About Speaker Relay! Hello everyone, Does the speaker relay turn on with out the output TRANSISTORS? Thank you!

5th February 2010, 08:14 PM	#2
nigelwright7557 diyAudio Member Join Date: Apr 2008 Location: Carlisle, England	The output transistors turn on before the relay does. There is usually a couple of second delay from when teh amp is powered up until the output is connected to the speakers. __________________ http://www.murtonpikesystems.co.uk PCBCAD40 pcb design software.

5th February 2010, 08:46 PM	#3
tommy1 diyAudio Member Join Date: Jan 2010	Thank you for relying. What I mean was "can the relay kick on if the OUTPUT TRANSISTORS WERE TAKEN OUT OF THE CIRCUIT BOARD?" Without the OUTPUT ...C: 33 Volts, Bass: 32 Volts, E: 0 Volts. When I put the OUTPUT back in the circuit board then the Bass turns to be zero Volts ???? Last edited by tommy1; 5th February 2010 at 08:54 PM.

6th February 2010, 02:29 PM	#6
5th element diyAudio Member Join Date: Oct 2002 Location: England	If the relay control circuit is designed properly it will not turn them on if there is any appreciable DC on the output of the amplifier. An amplifier without any output transistors might show one of the rail voltages on the output, this would stop the relays from closing. On the other hand, if the output transistors had blown and the rail fuses blew as a result, then there might be no DC on the output and the relays will close. That is if the relays and control circuitry are not powered after the amplifiers rail fuses. What is it that's gone wrong? __________________ What the hell are you screamin' for? Every five minutes there's a bomb or somethin'! I'm leavin! bzzzz! Droggon Attack!

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6th February 2010, 12:17 PM	#4
EchoWars diyAudio Member Join Date: Dec 2002 Location: Left of the Dial	Depends on what the removal of the transistors does to the feedback loop. So the answer here is 'maybe'. A schematic of your amp would help.

6th February 2010, 02:14 PM	#5
maxpou diyAudio Member Join Date: Apr 2006 Location: Québec	Hi Tommy1, why do you removed the output transistors? Maxpou

6th February 2010, 04:58 PM	#7
tommy1 diyAudio Member Join Date: Jan 2010	...ansewering to MAXPOU. I removed the output transistors for safety. However, the Amp is working execpt the relay does not kick on because of the IC C1237. I got the audio output before the relay. So far, I have replace the UPC1237HA. Thank you so much to all the friends in this forum !

8th February 2010, 09:10 PM	#8
kevvywevvywoo diyAudio Member Join Date: Aug 2008	what make and model amp is it?

8th February 2010, 09:53 PM	#9
tommy1 diyAudio Member Join Date: Jan 2010	The model # a-501 made by API

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