Pulse DC 60 htz

[Artic_Knight]

im trying to achieve a 60 htz or close dc pulse current for motor experiments. ive seen the 555 timer curcuit setup but what baffles me is there is not some thing simpler on the web that can easily scale up? ie 1/4 curcuits vs 100 watt curcuits.

perhaps the 555 timer is the way to go atleast for lower voltages but i wanted to see if anyone has a curcuit that may be more scaleable and simpler? a couple of mosfets tied together with a resistor for eg.

i tried to use the joule thief curcuit but unfortunately it generates a more solid current than pulse current. perhaps some inherent leakage from the transistor. also it pulses a bit too quick.

thanks for any ideas!

[Yucca]

Hi,

assuming you have 60Hz 120V wall current you can use 3 resistors accross the mains live and neutral like this:

(LIVE)-----[ 470k ]----[ 47k ]----[ 470k ]----(NEUTRAL)

the signal accross the 47k will be approx 6V AC.

use that signal to drive the gate of an N channel FET like IRF730:

connect -ve pole of your DC supply to one side of the 47k.
connect the FET gate to the other side of the 47k.
connect -ve pole of your DC supply to the FET source.
connect your load (pulse motor) accross +ve pole of supply and FET drain.

if you need to increase the rise and fall time of the pulses then put a FET driver IC before the gate.

Yucca.

[Artic_Knight]

thanks! thats a very good tip that i will use.

do you by chance know of a simple way to do it from dc? such as a battery or cap? i know of the 555 timer but i was thinking some arangement of mosfets was possible i was just not able to figure it out myself. something easy i could do with current parts.

good info thanks for the response!

[Yucca]

Easiest to use 555 and have that drive an N channel FET gate.
With 556 (2 x 555) you can also implement PWM.

if you wan´t to build your own then google "2 transistor astable multivibrator" you can vary the on time and off time, can use any general purpose transistors at that freq like 2n4401 etc. can drive a FET gate with the oscillator output.

[Artic_Knight]

thats fantastic, youve been very helpful! thanks a bunch!