[thedoc (OP)]

Parantap Nandi  asked the Naked Scientists:
   
Please tell me if 9V D.C can be stepped up to 220V D.C directly without any other device (oscillator).

Parantap Nandi

What do you think?

[Geezer]

No; you don't have to have a transformer, but you will need some device that periodically interrupts the current (an oscillator) from the 9V DC source.

[chris]

We had a gadget at school that plugged onto the top of those massive 6v oblong batteries; it produced outputs of up to 2000v I think.

[RD]

if you connected the 9V battery to a large inductor, (e.g. primary winding of a transformer), a momentary high voltage pulse is created when the circuit is broken via the back EMF.

https://en.wikipedia.org/wiki/Inductor#Stored_energy

The oscillator flashgun circuit in disposable (film) cameras charge a capacitor to around 300volts from a 1.5Volt battery ...

[distimpson]

Parantap Nandi  asked the Naked Scientists:
   
Please tell me if 9V D.C can be stepped up to 220V D.C directly without any other device (oscillator).

Parantap Nandi

What do you think?

connect twenty five 9VDC supplies in series to get 225VDC

[syhprum]

In the twenties you could get a gadget with ten twelve volt lead acid batteries that you charge in parallel from your car and then switch into series to run your wireless.

[Phractality]

You can connect a 9 vdc battery to an R-C oscillator to produce an a/c sine wave of about 9 volts peak-to-peak. Connect that a/c to the primary coil of a 1:25 step-up transformer, and the secondary will be about 220 volts peak-to-peak or 155 vac. Put that thru a full-wave rectifier to get 220 vdc. Of course if you put too much of a load on the circuit, the a/c will no longer be a sine wave, and the output voltage will decrease.
You can get higher voltages with the same transformer if you continually interrupted the current from a battery to the primary coil by rapidly switching the primary current on and off. Before we had transistors and solid-state relays, this was done by connecting a relay's output contacts in series with its own current.
The d/c voltage output of the vibrating switch is a square wave, but the primary current is more like a trapezoidal wave. A transformer with a 1:10 ratio will increase the voltage of a sine-wave input ten fold. But the output voltage depends on the rate at which the input current rises and falls. You might get 1:100 voltage increase from a 1:10 transformer.

[Geezer]

You can connect a 9 vdc battery to an R-C oscillator to produce an a/c sine wave of about 9 volts peak-to-peak. Connect that a/c to the primary coil of a 1:25 step-up transformer, and the secondary will be about 220 volts peak-to-peak or 155 vac. Put that thru a full-wave rectifier to get 220 vdc. Of course if you put too much of a load on the circuit, the a/c will no longer be a sine wave, and the output voltage will decrease.
You can get higher voltages with the same transformer if you continually interrupted the current from a battery to the primary coil by rapidly switching the primary current on and off. Before we had transistors and solid-state relays, this was done by connecting a relay's output contacts in series with its own current.
The d/c voltage output of the vibrating switch is a square wave, but the primary current is more like a trapezoidal wave. A transformer with a 1:10 ratio will increase the voltage of a sine-wave input ten fold. But the output voltage depends on the rate at which the input current rises and falls. You might get 1:100 voltage increase from a 1:10 transformer.

Yes, but the OP asked if it was possible without an oscillator.

[syhprum]

Many things are possible once you have an oscillator or some kind of switching but it is hard to devise a completely static way to do it , perhaps you could charge up a capaitor with a liquid dielectric and then let the liquid drain out or would that be cheating ?

[Geezer]

Many things are possible once you have an oscillator or some kind of switching but it is hard to devise a completely static way to do it , perhaps you could charge up a capaitor with a liquid dielectric and then let the liquid drain out or would that be cheating ?

That might work. Could you "stack up" charge by some mechanical "fire bucket" means, not so different from thunder clouds perhaps?