# Thread: Need help with Pulse DC

1. Here is what I have.
A pulsed DC signal that when displayed on my voltmeter it reads more than 1200 V and 200 ma @RMS. I measured it with ACV and DCV and it still read 1200. It pulses at least 80 times a second; but for some reason It doesn't have enough power to turn on a little flashlight bulb or a simple AA motor (both DC).

Any ideas on why it isn't powering anything?
Could the volt meter be giving off false readings?
Thanks,

2.

3. I wish I could help. Maybe the meters are draining the power? Placing the meters after the bulb-would that work?

4. Yes, I believe it's quite possible your meter is giving a false reading. If the light doesn't light, and it is rated for that voltage, that would be proof positive. The cheaper meters I think just read the peak voltage and give you a "rms" voltage that is .707 of the peak a-c. There is such a thing as a meter that reads "true rms."

5. It gave me a peak of over 1600v and 350ma so I thought I would round down. My meter is a cheap-o and it reads a AA battery as it should be and it reads the 110v coming from the wall. I will try a analog one, thanks.

Another question for you how do I create an frequency of over 1mhz (1,000,000 cycles per second)? I think that a welder operates around 1.2mhz but I am not sure.
Thanks,

6. Try this site for a design of a radio frequency oscillator.

http://my.integritynet.com.au/purdic/oscillators.htm

7. I need to create a electrical frequency between 1.5mhz and 2.6mhz. I would like it to operate with less than .01a and 250v. I understand how a LC circuit works and know how to read a basic schematic but am no sure about the simple things. I assume I need a circuit board, but what size inductor and capacitor do I need, what do i use to connect it to my solenoid, what would I use for the input? I want to keep things simple. I am not trying to be lazy but am just a little lost when it comes to the specifics.

Thanks for all the help,
Abudantia

8. Hi abudantia

First of its possible to have 1200V rms and 200 mA rms with 0 watts of real power. If your voltge and current spike occur out of sync then you will have no real power, it could almost be said that you have a very power power factor since all your power is imaginary.

Now im not sure i understand you right, you want to generate a signal, osscilating between 1.5 and 2.6 MHZ. As far as i know you cant generate a signal with a LC circuit, these circuits can be used as filters becouse they have a natural frequency at which they like to osscilate and reject the rest. However they cant create their own signals.

To create a signal you need something like a Wien bridge.
http://www.interq.or.jp/japan/se-inoue/e_ckt18_2.htm

But you dont want to make a sine wave right ? you want a series of pulses. Maybe you can attach a comparator to the output of the wien bridge to switch between two voltages values at a predefined value(i.e switch voltage between 5V and 0V when sine wave greater than 2.5V or so), not sure im gonna have to think about it a while.

 Bookmarks
##### Bookmarks
 Posting Permissions
 You may not post new threads You may not post replies You may not post attachments You may not edit your posts   BB code is On Smilies are On [IMG] code is On [VIDEO] code is On HTML code is Off Trackbacks are Off Pingbacks are Off Refbacks are On Terms of Use Agreement