Trying to find 1 v trigger relay

[Happyhopper]

Anyone know of a read relay at say 1 .v trigger?
 

[ledtester]

A bipolar transistor "triggers" at 0.7V and that can be used to drive a relay.

What's your ultimate goal?

[Happyhopper]

To use a mp3 player as a control for a 3 volt motor thank you for your help

[ledtester]

I'm going to guess that you want to trigger a relay when the audio level is greater than a certain amount. If that's not the case you gotta give us more details on what you really trying to do.

Here's a very straightforward idea:

- get a LM3916 and a 555
- build the standard VU-meter circuit that is described in the datasheet; there is also an instructable here:

https://www.instructables.com/id/LM3915LM3916-VU-Meter/

- the LM3916 VU-meter will operate from it's own supply, like +5V

- wire up the 555 as a "monostable multivibrator" which will activate a 5V relay on its output;

https://www.elprocus.com/monostable-multivibrator-using-555-timer/

- use one of the LED outputs of the LM3916 to activate the trigger input of the 555; which one you choose will determine the trigger level

[Audioguru again]

The LM3915 and LM3916 are obsolete, not made anymore and not in stock at Digikey.
The LM3914 is still made and available only in a tiny, impossible to solder, surface mount package.

[jeroen79]

To use a mp3 player as a control for a 3 volt motor thank you for your help

Can you elaborate on this?

[soldar]

Anyone know of a read relay at say 1 .v trigger?

Why do you open several threads and so cryptic?  Why don't you explain well what you want and all in one thread? Please don't waste people's time!

I would like to use my mp3 player as a signal generator to relay a3volt power supply , was going to make my own by use of a read relay question is there a better way
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