Dragon Tamer
Member
My big project right now is a radio that I have been building, I have run into a few problems. The first of which is the radio itself as started having conniptions and is blasting out 120Hz nose from the power supply. I have tried to do everything to fix this but nothing works. It should not be doing this since there is a 10,000uF capacitor in the circuit to handle this kind of problem, and the capacitor is still working. I have tried adding an LC low pass to the +V supply of the radio, but that did little to help.
I also have a relatively simple circuit that is in place to manage the heat that the power supply makes. At first the 555 that was working as the PWM portion of the main fan control was only delivering about 3.5V at 95% duty cycle to the fan and was doing next to nothing to help. Now for some reason it is delivering 8V to the fan regardless of duty cycle, and the fan is producing a lot of noise that is being picked up by the VU meter and causing it to display false dB levels. I don't know if it is because the 12V fan was briefly exposed to 15V or not (the 7812 failed).
I would appreciate any help you could provide on either subject, and yes I will be posting a schematic of the entire power supply later.
I also have a relatively simple circuit that is in place to manage the heat that the power supply makes. At first the 555 that was working as the PWM portion of the main fan control was only delivering about 3.5V at 95% duty cycle to the fan and was doing next to nothing to help. Now for some reason it is delivering 8V to the fan regardless of duty cycle, and the fan is producing a lot of noise that is being picked up by the VU meter and causing it to display false dB levels. I don't know if it is because the 12V fan was briefly exposed to 15V or not (the 7812 failed).
I would appreciate any help you could provide on either subject, and yes I will be posting a schematic of the entire power supply later.
