question ! lab power supply and lm3886 amp board ?

Thread Starter

pastinsain

Joined Aug 25, 2012
163
why can't my hp 10 amp 40volt lab power supply drive the lm3886 amp ?
the lm3886 works great with the 26vdc power supply that came with it, but when I try to power it with the hp 6267b lab supply , the amp will work for just a second then shuts down . Ive tried 3 other lab supplies and all do the same thing.
I have the current set up to 5 amps and the volts set to 26vdc and the amp shuts down every time.

now my ta2024 amps work great with the lab power supplies. what gives?
 

benta

Joined Dec 7, 2015
101
Normally, the LM3886 needs +26 V and -26 V.
It is possible to run it single,supply, but then the circuit needs to be configured so.
Are you certain that it is set up to run single-supply?
 

Thread Starter

pastinsain

Joined Aug 25, 2012
163
All three lab power supplies have the factory default jumpers connected.

Maybe if I tried connecting the neg jumpers on the rear of supplies to gnd . ?
 

Thread Starter

pastinsain

Joined Aug 25, 2012
163
Thanks , however, there is something about these lab supplies " the DC is different compared to the dc in an amplifier in regard to the lm3886.
that is for sure . What that difference is I would like to know ? I originally thought the lab supplies would be the cleanest power source you could drive an lm3886 with. but thats not the case ! bummer.
 

Thread Starter

pastinsain

Joined Aug 25, 2012
163
yes I have set the current to 2amps ,,3amps ,6amps 10amps and no go. I would like to think DC is DC. but not in this case.

I have tries 4 different PSUs and the same result
hp6267b
lambda 345a
Kepco JQE 36-15
HP 6289a
 

benta

Joined Dec 7, 2015
101
OK, for the last time:
the OP does not understand what a dual supply is.
The LM3886 needs a dual supply. And the original power supply will deliver +26/-26 V.
The lab supply only delivers +26 V. OK?

Benta.
 

Thread Starter

pastinsain

Joined Aug 25, 2012
163
the only dc power supply thats works is the one that came with the amp . What is so different about DC sources other than amp rating and regulated current limiting .
 

Thread Starter

pastinsain

Joined Aug 25, 2012
163
OK, for the last time:
the OP does not understand what a dual supply is.
The LM3886 needs a dual supply. And the original power supply will deliver +26/-26 V.
The lab supply only delivers +26 V. OK?

Benta.
The supply that works is the one that came with the amp. And it is a single DC supply.
 
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