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Reference voltage lower that expected
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Reference voltage lower that expected

by Razvysme on Fri Jul 24, 2020 8:10 am

Hello,

I bought a partial kit from a guy on a FB group, and started building it yesterday, following the build manual and reading the wiki.

I didn't get far because the reference voltage range is between 4.1 and 4.8V, nowhere near the 5.333. I triple checked the resistors, unsoldering one leg and measuring them, and they all comply with the specs. The diodes are all 4148, and the shunt is LM336Z-5.0. Any idea what might be wrong? Below you can see how far i got. Cheerios.

IMG_20200724_140013.jpg
IMG_20200724_140013.jpg (357.86 KiB) Viewed 77 times

Razvysme
 
Posts: 2
Joined: Fri Jul 24, 2020 8:00 am

Re: Reference voltage lower that expected

by Razvysme on Mon Jul 27, 2020 7:01 am

I got some voltages reading:

d44 d45 juncture - 0.54
d45 r5 juncture - 1.08
r5 tm6 juncture - 1.72
tm6 r4 juncture - 2.22
r4 d46 juncture - 3.62
d46 d47 juncture - 4.16
d47 r3 juncture - 4.70
r3 r2 juncture - 7.50 (26.0)
r2 r1 juncture - 7.91 (29.0)

lm7805 pin 3 - 4.98
78l06 pin 1 - 5.98

Razvysme
 
Posts: 2
Joined: Fri Jul 24, 2020 8:00 am

Please be positive and constructive with your questions and comments.