tnyswitch issue
Dear Sir,
I have designed AC input power supply for our application.Then we have chosen the same power supply for DC input by removing the rectifier and common mode choke at the input side.
AC input voltage: 85-300Vac
Direct DC input voltage: 110V - 420V DC
output voltage: 12V, 0.5A ,6W
The problem is, on the output side when we load 0.2A ,its output voltage is dropped from 12V to 0.5V....
i have attached diagram for your kind reference.. pls look at that and let me know how to solve this problem.
and also IS TNYSWITCH IS A OPEN LOOP REGULATION POWER SUPPLY? BECAUSE THERE IS NO PWM SIGNAL.. THE OPTOCOUPLER WILL BE TURNED ON, ONLY WHEN OUTPUT VOLTAGE EXCEED THE NOMINAL VALUE.OTHERWISE OPTO REMAINS OFF ,SO THERE IS A OPEN LOOP REGULATION ONLY (ie)..ON/OFF ONLY.. IS IT?
Comments
pls find the attached schematic..
Earlier Mail::::
I have designed AC input power supply for our application.Then we have chosen the same power supply for DC input by removing the rectifier and common mode choke at the input side.
AC input voltage: 85-300Vac
Direct DC input voltage: 110V - 420V DC
output voltage: 12V, 0.5A ,6W
The problem is, on the output side when we load 0.2A ,its output voltage is dropped from 12V to 0.5V....
i have attached diagram for your kind reference.. pls look at that and let me know how to solve this problem
Did you check the phase of your transformer as I asked you in my previous post?
talking about your schematic, what is what you have connected between pin 1 and 2 of your transformer? do actually have a winding? same question for pins 9-10 and 6-7.
Remove R7 from the circuit and place a short instead. Change R9 to 1K
I do not see your attached file.
I recommend you check the phase of your transformer. While the supply is running connect a scope probe to the DRAIN node. AT the same time see the positive leg of the transformer’s secondary winding. Both signals should have the same phase.
The tiny switch is an on/off regulator. Is not a PWM regulator. Any change in the output voltage and the controller responded very quickly to compensate for the change.