This is the 12v to 6v step-down circuit for you. When we want to use the radio carrying a car that uses a power supply of 12 volts, but these radios require a voltage about 5 to 8 volts.
Normally, We always use a 3 pin DC voltage regulator(IC78XX series) for this job. Which may be will apply number 7806 provides the voltage of 6 volts. But it does not a popular number. In my stores have IC-7805 is popular IC is applied in many digital circuits (5 volts power supply).
However, we modify a 7805 to the output of 6 volts in easily. When we add a chain of a diode such as 1N4148, in series at between the common pin of IC1 and Ground. It will increases the output by +0.7V for every diode used.
In the circuit below. We add 2 diodes (0.7V + 0.7V). Therefore, the voltage of output is 1.4V + 5V = 6.4V.
This way is easy if you have diodes in your store.
And both capacitors are used for absorbs or smooth a fluctuating signal as shown in Figure 1.
Building 12V to 6V converter
Since they use a few parts, so assemble them on perforated board or Universal PCB board. as Figure 2. We will see that the output voltage is voltage drop across both diodes (0.6V + 0.6V) puls with The IC voltage equals about 6.2 V approximately. (on digital multimeter shows 6.4 volts.)
The output current from the IC about 1-ampere max. It must be the heat sink to the IC with the current size. And Then we can increased output voltage in other sizes such as 8 volts so can use instead IC is number of LM7808, to add diodes into 4 pcs connected to IC-7805. again.
If this not working.
If IC1 is very hot please check pins and wiring again.
The output may be a short circuit.
Then, remove the load
next, measure voltage output when no load, should read about 6.4V.
If higher, please check IC1’s the ground pins and all diodes in series, the voltage across them should about 1.2V