# Voltage multiplier

Discussion in 'Electronic Basics' started by Roger Dewhurst, Sep 15, 2006.

1. ### Roger DewhurstGuest

Does a voltage multiplier always require AC or pulsed DC to run it? Are
there any types that will multiply unpulsed DC?

R

2. ### EeyoreGuest

Only those that create their own 'pulses' !

Graham

3. ### Bob EldGuest

Yes there are voltage multipliers that will multiply pulsed DC. The first
component of such a multiplier is a series capacitor. The output side of the
first stage is a diode to ground and another diode forward. The voltage at
this point is the peak-to-peak value of the original pulse train. In may be
filtered to a DC value of the pk-to-pk.and the process repeated for higher
voltages. Note: that the output of the series cap is an AC wave and that it
is offset by the diode arrangement. BTW the same circuit works for an AC
wave as well as pulsed DC because DC components do not go through the
capacitors.

4. ### Homer J SimpsonGuest

I cannot conceive of any way to step a voltage up without some form of
commutation. AC or pulsed DC are self commutating.

5. ### BanGuest

Those Electrons are lazy and won`t climb up to a higher potential by
themselves, just like water. You have either to

1.) kick them in the ass with an inductor
or
2.) lift them up with a switched capacitor (elevator) or a Van De Graaf
generator (rolling staires)
or
3.) swing them up and down with a transformer and dump them on the top with
a rectifier.
or
4.) convert their energy into something else (motion, light, heat) and then
back at a higher level.

For a beginner all these circuits are kind of complicated. You can buy

6. ### Guest

it does not depend on ac voltge,it can be operated on dc also

7. ### JeffMGuest

Yup. Like Ban said.
This is the one that sprang to my mind.

It's kinda like Ban's 2a.

Of course, the OP can buy black-box DC-DC converters that do this
(they use Technique #1 internally--as well as Eeyore's bit).

8. ### JamieGuest

you need some way of charging and discharging capacitors
and gain voltage.
since it is very picky about the littlest voltage drop..
i used Hex FETS, 555 Timer that modulated to form a
PWM circuit. the FETS are arranged in a logic state to
charge and discharge the caps in a series, i guess you could
call it a charge pump, a little different than what i have seen
any where how ever...
this unit uses large caps. and uses the original source along
with the charged source to regulate voltage..
there are no inductors at all in the circuit that play any roll
in increasing the voltage..
this thing works very good with very little noise generation.

P.S.
the Caps do get warm how ever, Low ESR is a must..