Tube DIY Asylum

Do It Yourself (DIY) paradise for tube and SET project builders.

Use this form to submit comments directly to the Asylum moderators for this forum. We're particularly interested in truly outstanding posts that might be added to our FAQs.
You may also use this form to provide feedback or to call attention to messages that may be in violation of our content rules.

You must login to use this feature.

Inmate Login

By default, logging in will set a session cookie that disappears when you close your browser. Clicking on the 'Remember my Moniker & Password' below will cause a permanent 'Login Cookie' to be set.

Moniker/Username: The Name that you picked or by default, your email. Forgot Moniker?	Examples "Rapper", "Bob W", "joe@aol.com".
Password:	Forgot Password?
	Remember my Moniker & Password ( What's this?)

If you don't have an Asylum Account, you can create one by clicking Here.

Our privacy policy can be reviewed by clicking Here.

Inmate Comments

From:
Your Email:
Subject:

Message Comments

Original Message

RE: My meter is scaled to 200 ma.

Posted by Triode_Kingdom on June 19, 2017 at 07:08:19:
Is this a panel meter you're discussing? If so, I would expect a 200mA meter not to need an external shunt. The only way to be certain is to rig up a variable power supply and fixed resistor for a test. For example, connect a 100 ohm resistor in series with the meter, then slowly begin applying voltage. If the needle goes to full scale quickly, it needs a shunt. Otherwise, it should read half scale (100mA) when you reach 10V.