Help me on Voltage Regulator LM 7806?

Hi guys,

I want to combine 5x LM 7806 in a circuit, can anyone help me out with the schematics. I've only know the basic schematic of LM 7806 as attached! 

Thanks :)

Picture of Help me on Voltage Regulator LM 7806?
iceng2 years ago

Granted if you have 6V AC the peak voltage is 6 x 1.414 = 8.5 volts

Less 1.5 for the rectifier leaves 7 volts WITH RIPPLE going below that.

Now you are short because the 7806 needs at least two additional volts (total_of_8v) to regulate down to 6 volts you desire !

You could buy the LDO version reducing the overhead to possibly 7v, however that still leaves the 120 cycle Ripple which will play hell with the servos.

That small 10 uF front end capacitor is way too small for the ripple, you really need several thousand uF or use 12volts.

Energy is the operative situation in reducing ripple in power supplies.

That is Energy = C*V*V/2 and that means if you double the voltage the capacitive requirement to limit ripple decreases by four times.....

6VAC DCsine.png
naqibzainudin (author) 2 years ago

Ok, noted! What i want to do is a POWER SUPPLY for my five servos. I have a center tapped transformers which is rated at 0 240 V / 6V 0 6V. They will be stepped down and will have a bridge rectifier. So from rectifier i will connect them with a 6V Voltage Regulator. From the Voltage regulator output, i will connect them with my servos. My question is do SINGLE 6V Voltage Regulator is okay to supply enough current for my five servos or do i need A 5 6V Voltage Regulator to supply enough current for each motor.

If you have a transformer that outputs 6V then why do you need a 6V regulator?

A silge 7806 will supply up to 1A of current. Should be enough to support 5 servos. If more current is needed you can add additional 7806 in parallel in the circuit.

rickharris2 years ago

Give us more information on what your wanting to do and why. Circuit design calls for more data than your supplying - Otherwise people are going to say look at the data sheet for the regulator.