Re: I need a switch can you help? IMPORTANT!
Breining, Jim C ( jimb7563@dmci.net )
Thu, 29 Jan 1998 20:04:23 -0500
At 01:04 PM 1/29/98 -0500, you wrote:
>On Fri, 30 Jan 1998, John Berry wrote:
>
>>
>> * A component of a circuit that will make and break the circuit so that
>> a pulsed DC will result from a constant voltage source.
>>
>>
>I am pretty sure there are high power solid state relays or SCR's out
>there that could easily handle 10A loads. I think stage lighting
>equipment used to use stuff like you are talking about. Check a good
>electronics supply house. If you get a solid-state relay, one with fast
>switching speed, you can drive it with your 555 IC and switch the high
>current DC. Good luck!
Hi John,
A solid state relay may work, depending on the current draw in the control
side. (How much current can a 555 timer switch directly?) There are several
mfg. that have these. Crydom, Potter & Brumfield, Philips ECG, NTE, etc. The
most common type switches 24-260 VAC with 3-32 VDC, however I have seen 2 that
will switch 0-100 VDC with 3-32 VDC at 10 and 40 amps. I don't think the
switching speed is a problem, most DC devices are faster than 50-100 Hz.
I'll get some specs, part numbers, etc. at work and post them tomorrow.
You mentioned a chopper circuit. These are used a lot for motor speed control
esp. in electric cars. Basically a control circuit switching 2 SCRs for
pulse width and/or frequency modulation to control an electric motor, and can
switch several hundred/thousand amps, depending on the SCR used. I don't have
much on chopper circuits but info on electric vehicles should provide you
with circuit details.
Hope this helps.
Jim