12 Volt Transformerless Power Supply
We can convert the high voltage ac into low voltage such as 5v 6v 9v 12v dc without using the transformer which is called transformerless power supply.
12 volt transformerless power supply. If a circuit requires very low. Circuit is simple voltage dropping capacitor of 225j is connected in series with phase line of ac this is a non polarised capacitors so it can be connected. Nowadays in many electrical and electronic equipment which are low cost they have a transformerless power supply system in this article i have tried to give you the knowledge about transformerless power supply. If you need to touch the negative rail or the positive rail and any earthed device such as a toaster to get killed.
Resistive type power supply on the other hand dissipates more heat so the power loss is quite high. The two basic types of transformerless power supplies are capacitive and resistive. Circuit diagram resistive transformer less power supply circuit diagram. Thus here excess energy is dissipated as heat across the voltage dropping resistor.
The above concept utilizes high voltage pp capacitors for dropping the mains voltage to the required level however it is unable to raise current levels as per any desired particular. Here is the circuit diagram and explanation for transformerless power supply. During one half wave the current flows via d1 through the load and back via d4 while during the other half wave it flows via d3 and d2. Each time i intend to use transformerless power supply to power microcontroller 8051 atmega328p and even a dc fan of 12v 1 4a i notice that they never get powered even though the power supply has been tested to produce the required 12v or 5v dc as the case may be.
Please i am having this issues with transformerless power supply. I have discussed a few transformerless power supply circuits in this blog which are good only with low power applications and tend to become less effective or useless with high current loads. Capacitive type is more efficient since its heat dissipation and power loss are very low. Resistive transformerless power supply.
Resistive transformer less power supply is similar to capacitor power supply except that instead of reactance it uses resistance to limit current. The only solution is enclosed with this circuit in a box with no outputs. The problem with this power supply is this will kill you as the current will flow through the diode and be lethal.