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You're either not 'well regulated' or you're attempting to pull more currentI have a circuit that is supposed to run on 9V. When I connect my 9V (well
regulated) power supply to the plug Im only reading ~2.2 V. What would
cause
this? Is the implication that there is a short to ground somewhere?
If the short is to gnd, you would be reading 0V. So probably an IC got itsI have a circuit that is supposed to run on 9V. When I connect my 9V
(well regulated) power supply to the plug Im only reading ~2.2 V.
What would cause this? Is the implication that there is a short to
ground somewhere?
"catfarm" <anonymous@catfarm.com> wrote in message
news:5LqdnY_qv8ykZcDfRVn-rQ@comcast.com...
I have a circuit that is supposed to run on 9V. When I connect my 9V
(well
regulated) power supply to the plug Im only reading ~2.2 V. What would
cause
this? Is the implication that there is a short to ground somewhere?
You're either not 'well regulated' or you're attempting to pull more
current
than
the regulator can supply.
How about telling us what the device is that you are powering and the
specs
of
the power supply.
The LM7809 is good to 1 amp but you will need at least 11 volt input to theIts an audio modulator. It uses 2x quad opamps (TL074) and some LED/CDs
pairs to modify the sound.
Interestingly enough when I pull the chips I read a nice 9V at the plug.
Putting in one chip drops the voltage to 3.7V. Bad chip? They aren't
getting warm when the circuit is running.
Im using a 9V source that comes from a 7809 and should be able to put out
500mA.
"catfarm" <anonymous@catfarm.com> wrote in message
news:C56dndvfYbogWMLfRVn-ow@comcast.com...
Its an audio modulator. It uses 2x quad opamps (TL074) and some LED/CDs
pairs to modify the sound.
Interestingly enough when I pull the chips I read a nice 9V at the plug.
Putting in one chip drops the voltage to 3.7V. Bad chip? They aren't
getting warm when the circuit is running.
Im using a 9V source that comes from a 7809 and should be able to put out
500mA.
The LM7809 is good to 1 amp but you will need at least 11 volt input to
the
regulator.
You can post a schematic on alt.binaries.schematics.electronic, that would
be
helpful. Off hand, it sounds like a power supply problem but you have no
details.
You might try connecting your power supply to a resistive load to see if
it
hangs
in there. 9v/.5A= 18 ohms would load your supply half way and let you
test
whether the voltage stays correct. The power dissipated in the load would
be
9v * .5 A = 4.5 Watts so use an appropriately rated resistor.
"Lord Garth" <LGarth@Tantalus.net> wrote in message
news:SoQ7e.1251$JJ2.107@newssvr12.news.prodigy.com...
"catfarm" <anonymous@catfarm.com> wrote in message
news:C56dndvfYbogWMLfRVn-ow@comcast.com...
Its an audio modulator. It uses 2x quad opamps (TL074) and some LED/CDs
pairs to modify the sound.
Interestingly enough when I pull the chips I read a nice 9V at the plug.
Putting in one chip drops the voltage to 3.7V. Bad chip? They aren't
getting warm when the circuit is running.
Im using a 9V source that comes from a 7809 and should be able to put out
500mA.
The LM7809 is good to 1 amp but you will need at least 11 volt input to
the
regulator.
You can post a schematic on alt.binaries.schematics.electronic, that would
be
helpful. Off hand, it sounds like a power supply problem but you have no
details.
You might try connecting your power supply to a resistive load to see if
it
hangs
in there. 9v/.5A= 18 ohms would load your supply half way and let you
test
whether the voltage stays correct. The power dissipated in the load would
be
9v * .5 A = 4.5 Watts so use an appropriately rated resistor.
Im not worried about the power supply. I use it for a variety of other
applications on a regular basis and it performs well. Its the circuit thats
problematic. Somewhere there is lots of power being dumped. I can't seem to
find out where though. It seems odd that the problem occurs when the opamp
chip(s) are inplace. I might try substituting in another batch of chips to
see what happens.
did you scope it for oscillation?
Im not worried about the power supply. I use it for a variety of
other
applications on a regular basis and it performs well. Its the
circuit thats
problematic. Somewhere there is lots of power being dumped. I can't
seem to
Maybe it is your specific load that makes the power supply oscillating.find out where though. It seems odd that the problem occurs when the
opamp
chip(s) are inplace. I might try substituting in another batch of
chips to
see what happens.
did you scope it for oscillation?
One thing you might try is removing the op amp and putting a resistorIts an audio modulator. It uses 2x quad opamps (TL074) and some
LED/CDs
pairs to modify the sound.
Interestingly enough when I pull the chips I read a nice 9V at the
plug.
Putting in one chip drops the voltage to 3.7V. Bad chip? They aren't
getting warm when the circuit is running.
Im using a 9V source that comes from a 7809 and should be able to put
out
500mA.
"Lord Garth" <LGarth@Tantalus.net> wrote in message
news:yUm7e.1017$zq4.138@newssvr11.news.prodigy.com...
"catfarm" <anonymous@catfarm.com> wrote in message
news:5LqdnY_qv8ykZcDfRVn-rQ@comcast.com...
I have a circuit that is supposed to run on 9V. When I connect my
9V
(well
regulated) power supply to the plug Im only reading ~2.2 V. What
would
cause
this? Is the implication that there is a short to ground
somewhere?
You're either not 'well regulated' or you're attempting to pull
more
current
than
the regulator can supply.
How about telling us what the device is that you are powering and
the
specs
of
the power supply.