Increase current of 78XX (up to 5A)

The circuit need a resistor of 40 ohms, R = 40.

Total resistor Rn of R1, R2 and R3 must be 40 ohms -->

1/R = 1/R1 + 1/R2 + 1/R3 = 3/Rn

Rn = R * 3

Rn = 40 * 3 = 120 ohms

Here R = Rn / 3 = 120 / 3 = 40 ohms

For R you need 1 watt per empere.

Here 3 x 1 watt = 3 watt for 3A.

For 4A you need 4 resistors of 1 Watt.

R1, R2, R3 and R4. Rn = 40 ohms x 4 = 160 ohms, 4 x 1 watt = 4 watts.

Or For 4A you need 2 resistors of 80 ohms 2 Watt or 1 resistors of 40 ohms 5 Watt.

For 5A you need 5 resistors of 1 Watt.

R1, R2, R3, R4 and R5. Rn = 40 ohms x 5 = 200 ohms, 5 x 1 watt = 5 watts.

Or 1 resistors of 40 ohms 5 Watt.

TIP122, TIP127 Pinout

 Type Number Regulation Voltage Mini Input Voltage  Recommended Max Input Voltage 7805 +5V +7V +35V 7806 +6V +8V +35V 7808 +8V +10.5V +35V 7885 +8.5V +11V +35V 7809 +9V +10.7V +35V 7812 +12V +14.5V +35V 7815 +15V +17.5V +35V 7818 +18V +21V +35V 7820 +20V +23V +40V 7824 +24V +27V +40V

Increase current of 79xx

Recherche personnalisée