Increase current of 78XX (up to 5A)
See also Increase current of 78LXX
Circuits Divers / Various Circuits
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