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Old 02-10-2010, 04:50 PM
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CON_ENG CON_ENG is offline
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Default impulse generator circuit

Hi every body ,
i am looking for a circuit that produce impulse signal as a part from my project i search in google and i found this circuit .G1 and G2 are gas discharge tube GDT .it is my first time to use this component and i'd like to know is this from 2-pole type or 3-pole. and if it was 2-pole why it's symbol had 3 point? i'd like to know how this work ?and if you had any limitations for using this circuit please, inform me.and if you had any other circuit can do the same function i'd be grateful
Regards
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Old 02-10-2010, 05:48 PM
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beenthere beenthere is offline
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It would be helpful to know the application of this circuit. Without an isolation transformer, the circuit is inherently unsafe to use at all.
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Old 02-11-2010, 06:30 AM
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i know that but i'll perform this circuit at a low level of voltage so i'll not need it or it will be not neccessary.
now i need to now the type of gas discharge tube, and certainly thanks.
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Old 02-11-2010, 09:30 AM
JDT JDT is offline
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The black dot in the symbol signifies that the tube is filled with gas.

These tubes change from insulating to low resistance at the voltages shown. They return to an insulating state when the current falls to some low value.

So in this circuit C3 charges up slowly through R3 and R4. When a voltage is reached, it will discharge quickly through G1 causing a cascade discharge through G2.

The circuit is not polarity sensitive so, depending on which button is pressed, pulses of either polarity can be produced.

Low voltage operation not possible! Take care!
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Old 02-11-2010, 11:21 AM
KMoffett KMoffett is offline
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Quote:
Originally Posted by CON_ENG View Post
i know that but i'll perform this circuit at a low level of voltage so i'll not need it or it will be not neccessary.
now i need to now the type of gas discharge tube, and certainly thanks.
Gas discharge tubes trigger in the 90VDC to 120VDC range, so the circuit can't be used with "a low level of voltage".

Ken
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Old 02-11-2010, 03:17 PM
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-so, the gas discharge tube used is from 2-pole type.
-i mean by low value of voltage is 500v value . i know that this circuit is not safe .
but i need a circuit that generate impulse signal and this is the avaliable one.
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Old 02-11-2010, 03:20 PM
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The circuit is simply a fatal accident waiting to happen.

Can you give any details about the pulse itself? What does it do and what are the necessary characteristics? There is probably a safe way to make your pulse.
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Old 02-11-2010, 03:22 PM
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Hello,

The circuit is not safe.
Take a look at a relaxation oscillator.
Here is an example using an UJT.
http://hyperphysics.phy-astr.gsu.edu...ic/relaxo.html

This is a link from the EDUCYPEDIA with oscillators:
http://educypedia.karadimov.info/ele...alogsquare.htm

Greetings,
Bertus
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Last edited by bertus; 03-15-2014 at 08:26 AM. Reason: corrected links
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Old 02-11-2010, 03:41 PM
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ok i need to generate an impulse signal such like lightning strikes but certainly not have the same value i need it as apart from my graduation poroject "lightning and surge protection in photovoltaic installations" so i don't had speciall characteristics except that i need it had an effective value with avery short duration .
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Old 02-11-2010, 04:47 PM
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That gives no useful parameters, like voltage and duration. You might think of using an ignition coil to make a high voltage. There is no connection to the power line, so you have a greater degree of safety involved, plus a greater voltage - http://www.madteddy.com/igncoil.htm
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