power supply query kindly help me out for this

[awais123]

Hi everyone ,
I want to generate a millivolt power supply having frequency range 1-25 Hz ,can anybody suggest me an easy and efficient way to make this

Muhammad Awais

 

[chuckey]

Millivolts are easy, just use an op amp with a gain <<1 and feed it from a pot across the Vcc line. 1- 25 HZ is tricky, do you want a sine wave, square wave, modulated DC? Its difficult to get a 25 : 1 change of frequency without having some sort of range switch. Also at 1 HZ, it might take 10 seconds to settle to the correct frequency and amplitude.
Frank

 

[Tunelabguy]

A power supply is normally thought of as something that supplies DC. So why are you talking about frequency ranges? Are you really asking about a millivolt signal source ? Or do you really intend to draw significant power from this "power supply"? Make your needs clearer and you might get some useful help.

 

[awais123]

Millivolts are easy, just use an op amp with a gain <<1 and feed it from a pot across the Vcc line. 1- 25 HZ is tricky, do you want a sine wave, square wave, modulated DC? Its difficult to get a 25 : 1 change of frequency without having some sort of range switch. Also at 1 HZ, it might take 10 seconds to settle to the correct frequency and amplitude.
Frank

actually i need square wave Sir...

 

[goldsmith]

Hi everyone ,
I want to generate a millivolt power supply having frequency range 1-25 Hz ,can anybody suggest me an easy and efficient way to make this

Muhammad Awais

Hi Muhammad
It depends on how much current do you need ! there are gang of ways available for your aim . e.g generating such a signal with high amplitude ( e.g 2 volts ) and then decreasing it via resistors or using a transistor and an op amp with a negative feedback through it's out put to do it , or ....
Best Wishes
Goldsmith

 

[Kuberkoos]

A astable 555 timer in with variable frequency output fed into a voltage divider to get the correct voltage would be my first suggestiom