Hello Everyone,
I have a 1965 Barracuda and I think the 5V voltage limiter for my gasoline and water temperature gauges is on its way out. There more about this device on this page:
http://www.allpar.com/history/mopar/electrical2.html
On my car, the voltage limiter is contained within the gasoline gauge and I think it would be easy to bypass it with fiber washer on the 12V gauge terminal. The Allpar article recommends replacing the mechanical limiter with a 7805 regulator. I checked the resistances in each gauge and both have 20 ohms. Full-scale on each of the sensors is 10 ohms. Each leg of the parallel circuit is 30 ohms so I calculate the total 5V draw from the instrument regulator would be 0.33 amps. I believe a 7805 regulator would have to dissipate up to 3.1 W of heat to run my gauges.
Building a instrument regulator based on a 7805 device would be straightforward enough but I thought I would see if there were any better way of doing this. From reading the posts here and on other sites, I've come across the following recommendations
I have a 1965 Barracuda and I think the 5V voltage limiter for my gasoline and water temperature gauges is on its way out. There more about this device on this page:
http://www.allpar.com/history/mopar/electrical2.html
On my car, the voltage limiter is contained within the gasoline gauge and I think it would be easy to bypass it with fiber washer on the 12V gauge terminal. The Allpar article recommends replacing the mechanical limiter with a 7805 regulator. I checked the resistances in each gauge and both have 20 ohms. Full-scale on each of the sensors is 10 ohms. Each leg of the parallel circuit is 30 ohms so I calculate the total 5V draw from the instrument regulator would be 0.33 amps. I believe a 7805 regulator would have to dissipate up to 3.1 W of heat to run my gauges.
Building a instrument regulator based on a 7805 device would be straightforward enough but I thought I would see if there were any better way of doing this. From reading the posts here and on other sites, I've come across the following recommendations
- use a cheap USB 12V car charger
- use an RTE Limiter
- use a DE-SW050 switching regulator