Simple driver for harvesting radiant spikes from a coil's collapsing field.

[Inquorate]

Hi all, didn't know where to post this but it would make a great battery / capacitor conditioner.

3 parts; the basic unit

Basic bedini coil voltage spike - Vox

The transistor driver;

Variable pulse width 555 - Vox

And the scr capacitor discharger

Pulse charge from cap by scr - Vox

Enjoy

[Ted Ewert]

Hi Ben,
I like your circuits. You may want to try a Sidac in the gate circuit of you cap pulser. I used one that way and it worked great. If you don't know what they are, here's a general description:
The sidac is a silicon bilateral voltage triggered switch with
greater power-handling capabilities than standard diacs. Upon
application of a voltage exceeding the sidac breakover voltage
point, the sidac switches on through a negative resistance region
to a low on-state voltage. Conduction continues until the current
is interrupted or drops below the minimum holding current of the
device.

These are really handy little devices. They only cost about $.50 each and come in a variety of voltages. Much better than a zener in this type of application.
Littlefuse makes them and you can find them at Mousers.

Ted

[boguslaw]

Hi Ben,
I like your circuits. You may want to try a Sidac in the gate circuit of you cap pulser. I used one that way and it worked great. If you don't know what they are, here's a general description:
The sidac is a silicon bilateral voltage triggered switch with
greater power-handling capabilities than standard diacs. Upon
application of a voltage exceeding the sidac breakover voltage
point, the sidac switches on through a negative resistance region
to a low on-state voltage. Conduction continues until the current
is interrupted or drops below the minimum holding current of the
device.

These are really handy little devices. They only cost about $.50 each and come in a variety of voltages. Much better than a zener in this type of application.
Littlefuse makes them and you can find them at Mousers.

Ted

Can you compare it with transil ? Transient voltage suppression diode - Wikipedia, the free encyclopedia

What is better ? How much power can SIDAC conduct ?

[Ted Ewert]

Can you compare it with transil ? Transient voltage suppression diode - Wikipedia, the free encyclopedia

What is better ? How much power can SIDAC conduct ?

These are two different devices. The transil apparently acts much like a zener diode, clamping a circuit to a set voltage and shunting any excess voltage.
A sidac becomes a short circuit at it's threshold voltage and only resets when the current ceases. They are primarily designed for use in AC applications. They are relatively low current devices typically handling 1 amp of continuous current with a surge of around 20 A.
I would recommend researching this whole family of devices. Lots of possibilities for the types of circuits we build.

Cheers,

Ted

[boguslaw]

These are two different devices. The transil apparently acts much like a zener diode, clamping a circuit to a set voltage and shunting any excess voltage.
A sidac becomes a short circuit at it's threshold voltage and only resets when the current ceases. They are primarily designed for use in AC applications. They are relatively low current devices typically handling 1 amp of continuous current with a surge of around 20 A.
I would recommend researching this whole family of devices. Lots of possibilities for the types of circuits we build.

Cheers,

Ted

Please , can you explain what do you mean by selected statement ? I've used this device to protect mosfet but I really do not fully understand how it works ? Does it conduct above selected voltage for example when circuit has flyback spike of 300V or it closes when such voltage tries to flow across it ?
Please , it is important for me to fully understand it.I've always thought that it works like a sparkgap passing currents related to voltage above selected level.