Hello' I have built a mic amp and wanted to check the wave form on a scope but when I connect the probes to the o/p of the amp the power supply trips (The Mic operates on 9 volt single rail.) I connected the scopes ground probe to the -ve (common) and the output to the other probe. the scope works alright with a signal generator. The Mic also works on a power Amp but with some noise. What might be the problem?
Is one of your scope probes a GROUND connection? Couple to the microphone amp output through a coupling transformer, see if that helps.
Which power supply trips, the scope, or the microphone amp? What are the specifications of that power supply?
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Thanks no the ground connection of the scope is connected directly to the Amp Its the power supply connected to the amp that trips or reads about 4 volts instead of 9v The current of the PSU was set to 1 Ampere. Please, generally, how do you check the responds of an audio Amp on the scope? I mean how the probes are connected.
.Thanks . no the ground connection of the scope is connected directly to the .Amp .Its the power supply connected to the amp that trips or reads about 4 .volts instead of 9v .The current of the PSU was set to 1 Ampere. .Please, generally, how do you check the responds of an audio Amp on .the scope? I mean how the probes are connected.
Do you have a two channel scope? Can you invert and add one of the channels? If so, make a differential connection to the output with the scope ground connected to the chassis ground of the amp. Put the inverted probe on the low side of the output and the non-inverted probe on the high side. The vertical gain for both channels must be the same and in the calibrated mode.
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I suspect the original poster doesn't know much about electronics. We should stop trying to help him, and ask that he find someone "local" (in his own country) who can explain how to use test equipment.
On 6/30/2010 4:47 PM William Sommerwerck spake thus:
Don't you think it's just a mite too early to give up on him (her)? Ask some more questions. They obviously didn't provide us with enough information; we know how to easily fix that problem.
-- The fashion in killing has an insouciant, flirty style this spring, with the flaunting of well-defined muscle, wrapped in flags. - Comment from an article on Antiwar.com (http://antiwar.com)
He's obviously making some gross error, but can't explain exactly /what/ he's doing. That's all the more reason for asking him to look for local help.
This is not unlike trying to explain to someone on the other side of the world how to tie shoelaces.
On Wed, 30 Jun 2010 17:40:49 -0700, William Sommerwerck ??o??:
Bunny Ears Probably the most common method for teaching kids to tie their own shoes is the "Bunny Ears" method.
Tell the child that he needs to make his shoe laces into "bunny ears." First, he needs to secure a knot for the bunny's head. Take the laces and cross them over to make an "X". Then, pull one ear through the bottom of the "X" and pull tight.
Say, "Now we need to give bunny some ears." Loop the laces into "bunny ears".
Tell the child that now we need to "make the bunny ears tight so they don't fall off". Then make another "X" using the "bunny ears", slide one "ear" under the "X" and pull tightly.
Plagiarized from:
On 6/30/2010 5:59 PM Meat Plow spake thus:
[...]Ackshooly, the way I heard it taught over here (U.S.) was similar, but more along the lines of making a bunny (to make the first loop), then "chasing the bunny around the stump" to complete the tie.
Dang, now I won't be able to tie my shoes at all ...
-- The fashion in killing has an insouciant, flirty style this spring, with the flaunting of well-defined muscle, wrapped in flags. - Comment from an article on Antiwar.com (http://antiwar.com)
riiight... now he can tie his shoes, all that remains is to tell him how to hook his scope across the output of his amp!
Sheesh
I think PETA would object.
On 7/1/2010 5:15 AM William Sommerwerck spake thus:
But no bunnies were harmed in this metaphorical example ...
-- The fashion in killing has an insouciant, flirty style this spring, with the flaunting of well-defined muscle, wrapped in flags. - Comment from an article on Antiwar.com (http://antiwar.com)
It's the principle of the thing!
"I say unto you, that whoever harms a bunny in his thought, has as much harmed the bunny in its body."
on a
need a good explanation of what is in that power supply
or, how about float the power supply, even better, use a battery.
then you should be able to connect your scope ground anywhere on the circuit. just make sure your mike, amplifier, and power supply are all floating.
Usually one connects the ground of the scope to the system's reference point, also called ground, and connects the input of scope to the output of the amplifier. If the output of the amplifier is an 'H' drive, you will need two input probes, one for each output leg.
If you get the amplifier up and running there's a way to use your sound card in your PC to explore what is happening at different frequencies and what the bandwidth of your system is.
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