please delete :/.
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Last edited by lifthanger; 01-18-2011, 04:39 AM. -
Re: Multisim troubles
Are you trying to design a common emitter amplifier? If so, you have your top base resistor wired to the wrong place. Edit: Just threw it in LTSpice - it does swing negative due to the input signal. There are two things wrong in your circuit.
#1. Your biasing is wrong.
#2. Your input signal is too high in amplitude. 7 volts AC peak is 14 volts p-p. The DC supply voltage needs to be at least this value minus the voltage drop of the transistor. Since you are not using a split supply, your DC supply is 12 volts. And since you're trying to get some gain as well... all you will get is a square wave with DC offset on the output.Last edited by Th3_uN1Qu3; 01-18-2011, 04:47 AM.A working TV? How boring!Originally posted by PeteS in CA
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Hi everyone,
Brought a non functionnal PS5. Apparently only a bad PSU...
No beep, nothing.
After some tests i found this :
- PSU is fine (12 volts stable)
- 12 volts line is shorted
- DA9065 was fried, F7003 also => Replaced both of them, short is gone on 12 volts line, no dead short anywhere else.
- By the way, nothing change. No signal, no power, no beep.
Mesuring all rails with my workbench psu (12 volts input)
- 0.00 amp drawing
- 12 volts, 5 volts, 2 volts, 1,15 volts are presents (suppose new DA9065 do is... -
Hello,
Dell Latitude 5420 P137G
Board: LA-K491P REV A01
I have received this laptop which was described as "does not power on or accept charge." Battery shows no sign of charging when charger is plugged in, nor does the board show any signs of life when battery is unplugged and charger is plugged in. No light from the LED at all or any other indications of activity.
Board seems to have no shorts, all power rails are fine and show high resistance.
When charger is plugged in, voltage is present in 3.3V rail but absent in others.... -
I have this 10 amp 0 to 30 volt switching power supply that decided to have a 630 milliamperes draw on it at 0 volts
I open it up to find non brands name capacitors in it
I am not sure how this switching power supply is set up
Could someone please explain how this power supply works
Here is the capacitor ESR results
(1) 47uf@50 volts 0.46
(2) 47uf@50 volts 0.45
New 47uf@50 volts 0.35
(1) 100uf@25 volts 0.34
(2) 100uf@25 volts 0.35
New 120uf@50 volts 0.08
(1) 220@25 volts 0.13... -
Hello everybody, I could use some help on this one... It's got me guessing...
I took pictures of all the boards and the pin out of the connector on the power supply that goes to the main board... I measured all the pins in relation to chassis ground, here are the result.
(B13v)1. 12.7 volts cycling (Vamp) 2. 12.7 volts cycling
(B13v)3. 12.7 volts cycling (PWM5) 4. 1.0 volts cycling
(OD_LE)5. 2.8 volts cycling (PWM4) 6. 0.9 volts cycling
(OD_ON)7. 2.8 volts cycling (PWM3) 8. 0.9 volts cycling
9. ground (PWM2) 10. 0.9 volts cycling... -
The primary voltage is 480 single phase the second voltage needed is 60 volts
Now it could be 30 volts 0 volts 30 volts preferred
Or it could be 60 volts 0 volts 60 volts and just use one side of
Output amp need to be at least 30
Dose anyone know where I can find one
This is what is the device I am working on
The problem with this one is that it is over heating and smelling like it is over heating
When it has a load on it...
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