adafruit industries

kokoon · Post by **kokoon** » Mon Feb 27, 2006 6:46 pm

i have a good 5.33V at pin1 but pin3 is only 10.06V... the manual says 12V +/- 1V so i guess that's not good enough. or is it? what should i do?

thanks guys!

guest · Post by **guest** » Mon Feb 27, 2006 8:17 pm

check to see if r178 and r179
are of the correct value and soldered well

also check the voltage at pin8 of ic23
it should be higher than 14v

kokoon · Post by **kokoon** » Tue Feb 28, 2006 3:21 am

is that voltage really too low? i haven't checked yet but i'm pretty sure the values are correct... maybe the resistors are a bit too much off (they're 5% after all)? is that voltage supposed to be really precise?

guest · Post by **guest** » Tue Feb 28, 2006 7:29 am

to get as low as 10.2v there would need
to be 15% error on those resistors
and each one would have to error
in the correct direction

the voltage itself isnt all too critical
but it is indicitive that something is wrong
and its better to have it fixed now
before it causes trouble later

kokoon · Post by **kokoon** » Tue Feb 28, 2006 9:29 am

okay cheers i'll check it out when i get home from work.

kokoon · Post by **kokoon** » Tue Feb 28, 2006 12:58 pm

pin8 of IC12 is only 11.40V r178 and r179 are correct values and are within 5%. now what? is the opamp faulty?

kokoon · Post by **kokoon** » Tue Feb 28, 2006 1:03 pm

allright, everything is allright - the initial voltage (from the wallwart) was too low

11.81 now so it's cool! thanks anyway!

adafruit industries

solved: psu j4 voltages

solved: psu j4 voltages