Hey Diy Family!
I build power supply for my guitar pedals. It's based on LM317T voltage regulators which can handle 1.5A. the circuit is simple. Diode rectifire, couple 1000uf cap, 0.1uf cap, then it's going to input of regulator and after output there is 1uf tantalum and 470uf electrolytics. There is resistor, cap and trimpot going in to the regulator to regulate voltage. Simple circuit. So what i did is I took 14V 3.5A toroidal transformer and pluged circuit to it. Everything works quite and well. Then I soldered 10 same circuits and plugged in to the same transformer. So it looks like that from transformer is going in to the 10 same circuits and after to ten gt pedals.
When I plug 6 pedals which need small mA it works well but when i plug pedal which needs more, like 250 mA there is a big hum coming out of amplifier. To my counting transformer can handle much more current and each circuit can handle more then 500mA easily, why is there hum coming out? Because when I unplug other pedals and plug in one that needs more current it works well, quite with no hum. When i plug other without this one, there is no hum but if plug together there is a big hum. why?
Thanks
I build power supply for my guitar pedals. It's based on LM317T voltage regulators which can handle 1.5A. the circuit is simple. Diode rectifire, couple 1000uf cap, 0.1uf cap, then it's going to input of regulator and after output there is 1uf tantalum and 470uf electrolytics. There is resistor, cap and trimpot going in to the regulator to regulate voltage. Simple circuit. So what i did is I took 14V 3.5A toroidal transformer and pluged circuit to it. Everything works quite and well. Then I soldered 10 same circuits and plugged in to the same transformer. So it looks like that from transformer is going in to the 10 same circuits and after to ten gt pedals.
When I plug 6 pedals which need small mA it works well but when i plug pedal which needs more, like 250 mA there is a big hum coming out of amplifier. To my counting transformer can handle much more current and each circuit can handle more then 500mA easily, why is there hum coming out? Because when I unplug other pedals and plug in one that needs more current it works well, quite with no hum. When i plug other without this one, there is no hum but if plug together there is a big hum. why?
Thanks