RE: LM317 Failure

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RE: LM317 Failure

Posted by Caucasian Blackplate (P) on January 24, 2016 at 12:54:27

In Reply to: LM317 Failure posted by Triode_Kingdom on January 23, 2016 at 22:19:54:

Hmm, let's have a look at this. The LM317 has a temperature rise of 55-65 degrees C per Watt dissipated (depends on whether you get the insulated one or not). I like to assume that an amp chassis will be on the warm side (40C), and that anything over 100C is asking for trouble, so 1 Watt of dissipation without a heatsink is sort of reasonable.

I don't know what the bias voltage would be in the RH amp, but I suspect it could be around 20V, in which case the 317 is going to get very hot and fail in relatively short order.

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Follow Ups Full Thread

Topic - Schade feedback or RH amp with fixed bias? - DAK 00:44:04 01/23/16 (15)

RE: Schade feedback or RH amp with fixed bias? - Chip647 07:57:50 01/23/16 (14)

RE: Schade feedback or RH amp with fixed bias? - DAK 08:15:41 01/23/16 (13)

RE: Schade feedback or RH amp with fixed bias? - Chip647 09:16:03 01/23/16 (12)

RE: I have been using the LM317 on low power amps - DAK 10:39:35 01/23/16 (11)

LM317 Failure - Triode_Kingdom 22:19:54 01/23/16 (7)

RE: LM317 Failure - Caucasian Blackplate 12:54:27 01/24/16 (0)

RE: LM317 Failure - DAK 22:48:16 01/23/16 (5)

RE: LM317 Failure - Triode_Kingdom 08:34:18 01/24/16 (4)

RE: It is the RH universal amp. - DAK 09:41:31 01/24/16 (3)

RE: It is the RH universal amp. - Triode_Kingdom 12:07:20 01/24/16 (2)

RE: I tried it in a PPP EL84 amp.... - DAK 12:53:55 01/24/16 (1)

RE: I tried it in a PPP EL84 amp.... - Triode_Kingdom 16:12:33 01/24/16 (0)

RE: I have been using the LM317 on low power amps - JKT 12:07:12 01/23/16 (2)

RE: I have been using the LM317 on low power amps - DAK 18:17:11 01/23/16 (0)

RE: I am very interested - DAK 14:22:46 01/23/16 (0)

Follow Ups

RE: LM317 Failure - Caucasian Blackplate 12:54:27 01/24/16 (0)

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