Low-Noise 7805/7812 Drop-In Replacements

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root42

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Published on March 8, 2024 7:03:05 AM ● Video Link: https://www.youtube.com/watch?v=N0dBU4isJ8Y

Duration: 41:54

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Linear voltage regulators such as the 7805 and 7812 are ubiquitous in vintage electronic equipment, and especially in home computers of the late 1970s and early 1980s. They have many advantages are very reliable. Their biggest drawback is their heat dissipation. The variants in metal TO3 packages are only available used or as new old stock. So if you want to replace them with a cooler running variant these brand new drop in replacements based on modern switching regulators might be worth a try. These particular variants have extremely low switching noise, so should be very usable in devices such as the Commodore 1541 floppy drive. So we will repair one of my broken 1541s and also fit it with the modern DR340 voltage regulator!

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Music: A Little Wonder by Spino2006

Original thread on DOSReloaded (German): https://dosreloaded.de/forum/thread/7306-sammelbestellung-dr340-drop-in-positive-switching-regulator-to-3-lm340-lm323-lm7/?postID=252620&highlight=schaltregler#post252620

0:00 Introduction
4:50 The DR340 Regulator
7:35 Voltage comparisons
18:56 Oscilloscope Time
21:10 Modding the 1541
26:17 An Unexpected Repair!
36:02 Oscilloscope Time Again!
40:58 Outro