I need a 2.5 vdc to 12 vdc circuit

Printed From: the12volt.com
Forum Name: Motorcycle Electronics
Forum Discription: Installing Stereos, Alarms, Remote Starters, Lights, Garage Door Openers and other electronics on motorcycles.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=88844
Printed Date: May 08, 2025 at 3:37 AM

Topic: I need a 2.5 vdc to 12 vdc circuit

Posted By: marshal_mercer
Subject: I need a 2.5 vdc to 12 vdc circuit
Date Posted: January 12, 2007 at 9:15 PM

Hi, all:

I'm a novice at electronics who would like to have a 2.5 vdc to 12 vdc boost converter made but don't know enough to figure out the resistor, capacitor, and coil values to do it myself. Any takers? I'm happy to pay for the work.

This is a personal item, not for resale. It does not have to look pretty; it just has to do the job. What job? I want to trigger a 12 volt relay from a 2.5 volt dc switch. I think that the relay requires about 150 mAmps at 12 volts to trip it. Why? To disengage a cruise control from the clutch switch on a motorcycle. The cruise control has a brake-switch disengage. I want to add the clutch-switch disengage feature.

Please PM me, or contact me at mhmercer@earthlink.net to talk about this. I'm in southern California, if that matters.

Thanks,

Marshal

Replies:

Posted By: CutDog504
Date Posted: January 15, 2007 at 11:16 AM

A PAC tr-7 module can do that.

Posted By: hotwaterwizard
Date Posted: January 15, 2007 at 10:14 PM

Does the motorcycle have a 12v battery?

Why do you need to convert 2,5 volts up when you have 12 volts already. You could just use a transistor to do the job. use the 2.5v to bias the transistor and the transistor makes 12v flow thru it.

-------------
John DeRosa (Hotwaterwizard)
Stockton California
When in doubt, try it out !

Posted By: marshal_mercer
Date Posted: January 17, 2007 at 10:34 PM

hotwaterwizard wrote:

Does the motorcycle have a 12v battery?

Why do you need to convert 2,5 volts up when you have 12 volts already. You could just use a transistor to do the job. use the 2.5v to bias the transistor and the transistor makes 12v flow thru it.

Thanks to all who contributed to this discussion.

I completed the project by using a lever-style momentary switch, activated by the clutch lever. I can pipe whatever voltage through it that I choose. I'll use two diodes to prevent back-flow to either the new switch or the brake switch. Simple. Done.

The main problem that I encountered with my first plan was that the clutch switch does not engage until it is very nearly though it entire stroke, too late for my needs. By making a bracket, then mounting the momentary switch, I can adjust the switching event to suit the situation.

Thanks again,

Marshal