Best for: Beginners, high reliability, low cost.
The LM7812 regulates the voltage. By placing a low-value resistor (around 3-5 ohms) across the input and output of the TIP2955 transistor, the transistor "turns on" once the current draw exceeds a few hundred milliamps, taking the 5A load off the regulator. 12v 5 amp power supply circuit
A 12V 5A power supply is a workhorse in the world of electronics. It is powerful enough to drive LED strips, charge Li-Po batteries, run 3D printers, power external hard drives, and serve as a benchtop supply for testing automotive electronics. Best for: Beginners, high reliability, low cost
| Component | Value / Part Number | Description | | :--- | :--- | :--- | | | UC3843 or UC3845 | Current Mode PWM Controller (DIP-8) | | MOSFET | IRF740 or 2SK2611 | N-Channel Power MOSFET (High Voltage) | | Transformer | EE35 / EE42 Core | Custom wound (Primary: ~60 turns, Secondary: ~6 turns, Aux: ~5 turns)* | | Fast Recovery Diode | SR560 or MBR20100CT | Schottky Barrier Diode (For output rectification) | | Bridge Rectifier | KBP206 | 600V 2A Bridge | | Input Cap | 47uF 400V | Electrolytic Capacitor | | Output Cap | 2200uF 16V x 2 | Low ESR Electrolytic Capacitors | | Diode | UF4007 | Ultra-fast recovery (for clamp circuit) | A 12V 5A power supply is a workhorse
100µF / 25V and 0.1µF ceramic for high-frequency noise filtering.
Vout = 1.25 × (1 + R2/R1)