• Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

2 Amp power supply

Status
Not open for further replies.

Narmer

New Member
hi every one
im new to electronics so i thought i might get good advises from this website

i was using 12 V DC power supply 2 Amp max and i dragged too much current from it unfortune without using circuit breaker as usual
any way the internal fuse blow up so i opened the circuit and installed new one 2 amp fuse
the fuse did break again when powering the circuit this time so i made a jumper and notice what would happen
i found out that the first inductor which is installed at first of the circuit in the ac line which is about 4 Micro H is heating up too much and going to smoke from heat so i switch off the circuit
does any one knows what would be the cause of that fault in circuit
thx
 

MikeMl

Well-Known Member
Most Helpful Member
Burned up transformer. You likely blew the diodes the first time you overloaded it. You likely burned up the transformer winding when you shorted out the fuse with a wire jumper. Baaadd way to do troubleshooting. Fuses are there for a reason...
 

crutschow

Well-Known Member
Most Helpful Member
Next time you troubleshoot something with a short, use a resistor or light bulb of the appropriate rating to substitute for the fuse. :rolleyes:
 

Narmer

New Member
thx alot for that light bulb tip , i did test the components again for voltage drops and found short but not in the first 4 bridge rectifier i found it at diode zenor 2 of them got shorted and power transistor got closed circuits at its 3 pins and small signal transistor . unfortunately cause of lake of components in my town i have tried to use some components i had from other old power circuits isnt the same exactly any way nothing to loose from trying . after replacing the old components . the circuit still have the short but the funny thing the light bulb did
flicker after about 10 seconds of powering and kept lighting but the circuit did turn on while the short is still exist there in the same time the voltage did raise to output 17 dc volts ( usually should be 14 volts max with potentiometer ) and only small resistor i think its like 1/4 wat 100 ohm heating up . is there any logic reason why it did turn on while the short is still exist
thx again
 

Narmer

New Member
another thing does any one knows how to test smps transformer out of the circuit . it has alot of inputs in the primary and alot of outputs in secondary
i have tried to test old one i had with putting about 9 volts dc in primary and measure the potential difference if its taking any current in it
problem that at secondary was getting like mili volts which hard to notice if its from the voltage i put at primary or from some kind of magnetic field at multimeter probs
 
Status
Not open for further replies.

Latest threads

EE World Online Articles

Loading
Top