Building a symmetrical psu B1 buffer - Page 19

udailey · 6th October 2009, 07:07 PM

Okay, no music. No relay click. The LED near the LM7805 is not on. I get 5V and 10V on BC556 and 2SK170 in the B1 circuit.
I get 5V from the LM7805 and 5V across the parallel resistors that feed the relay. I also get 5V on 2k2 feeding LED. Suppose I should replace LED.
Ri

Salas · 6th October 2009, 07:15 PM

npapp:

4 non matched Leds and 1k trimmers connected as rheostats instead of the fifth Led. Use pins in the 5th place and crocodile clips, so you will not unsolder anything and destroy the pads. After you set it, measure the trimmers and substitute resistors upright soldered on those pins. They will be different.

udailey · 6th October 2009, 07:15 PM

Used 9V battery and 100R resistor and tested relay. It works.
Uriah

Salas · 6th October 2009, 07:17 PM

Quote:

Originally Posted by udailey

Okay, no music. No relay click. The LED near the LM7805 is not on. I get 5V and 10V on BC556 and 2SK170 in the B1 circuit.
I get 5V from the LM7805 and 5V across the parallel resistors that feed the relay. I also get 5V on 2k2 feeding LED. Suppose I should replace LED.
Ri

7805?

7812 hello!

billyk · 6th October 2009, 07:23 PM

Quote:

Originally Posted by Salas

7805?

7812 hello!

Beat me to it!

udailey · 6th October 2009, 07:26 PM

Hey be gentle

I thought if using 5V relay we are to use 7805, no?

billyk · 6th October 2009, 07:37 PM

Logical conclusion, but that is what the resistors are for. It is jumpered for 12v relay and the resistors are for the 5v relays.

udailey · 6th October 2009, 07:40 PM

Okay. I had read Jean Paul talking about 5V relays and 7805 so I just assumed. Well thats easy. Be right back

Salas · 6th October 2009, 07:43 PM

Don't go jumper the resistors and keep the 7805. Without 7812 the driving circuit won't open. Its 7812, jumper, 12V relay, or 7812, resistors, 5V relay. No 7805.

npapp · 6th October 2009, 08:31 PM

Quote:

Originally Posted by Salas

npapp:

4 non matched Leds and 1k trimmers connected as rheostats instead of the fifth Led. Use pins in the 5th place and crocodile clips, so you will not unsolder anything and destroy the pads. After you set it, measure the trimmers and substitute resistors upright soldered on those pins. They will be different.

Perfect, thanks I will report back soon.

6th October 2009, 07:07 PM	#181
udailey Passive Aggressive diyAudio Member Join Date: Mar 2008	Okay, no music. No relay click. The LED near the LM7805 is not on. I get 5V and 10V on BC556 and 2SK170 in the B1 circuit. I get 5V from the LM7805 and 5V across the parallel resistors that feed the relay. I also get 5V on 2k2 feeding LED. Suppose I should replace LED. Ri __________________ You can purchase LDRs anytime to build a standard LDR attenuator or to build my new LDR Attenuator "A Lighter Note". Email me. diyldr@gmail.com

6th October 2009, 07:15 PM	#183
udailey Passive Aggressive diyAudio Member Join Date: Mar 2008	Used 9V battery and 100R resistor and tested relay. It works. Uriah __________________ You can purchase LDRs anytime to build a standard LDR attenuator or to build my new LDR Attenuator "A Lighter Note". Email me. diyldr@gmail.com

6th October 2009, 07:26 PM	#186
udailey Passive Aggressive diyAudio Member Join Date: Mar 2008	Hey be gentle I thought if using 5V relay we are to use 7805, no? __________________ You can purchase LDRs anytime to build a standard LDR attenuator or to build my new LDR Attenuator "A Lighter Note". Email me. diyldr@gmail.com

6th October 2009, 07:40 PM	#188
udailey Passive Aggressive diyAudio Member Join Date: Mar 2008	Okay. I had read Jean Paul talking about 5V relays and 7805 so I just assumed. Well thats easy. Be right back __________________ You can purchase LDRs anytime to build a standard LDR attenuator or to build my new LDR Attenuator "A Lighter Note". Email me. diyldr@gmail.com

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6th October 2009, 07:15 PM	#182
Salas diyAudio Chief Moderator Join Date: Oct 2002 Location: Athens-Greece	npapp: 4 non matched Leds and 1k trimmers connected as rheostats instead of the fifth Led. Use pins in the 5th place and crocodile clips, so you will not unsolder anything and destroy the pads. After you set it, measure the trimmers and substitute resistors upright soldered on those pins. They will be different.

6th October 2009, 07:37 PM	#187
billyk diyAudio Member Join Date: Oct 2005 Location: North Central Mass, USA	Logical conclusion, but that is what the resistors are for. It is jumpered for 12v relay and the resistors are for the 5v relays.

6th October 2009, 07:43 PM	#189
Salas diyAudio Chief Moderator Join Date: Oct 2002 Location: Athens-Greece	Don't go jumper the resistors and keep the 7805. Without 7812 the driving circuit won't open. Its 7812, jumper, 12V relay, or 7812, resistors, 5V relay. No 7805.

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