24V Stereo

[Dickjr.]

I got into this type thing today , I bought a Komatsu D39 with cab , had all components but the actual head unit for stereo. Dealer wanted 500$ for a radio , my PSR told me to get an aftermarket it would fit right in etc. Come to find out the power source in the plug was 24volt. I went to radio shack and picked up two of the 7812 . I was told by a local automotive electronic specialist that they would not work , would burn out fast etc. I do have the heat sinks to put on them. What's the longevity of these inexpensive little boogers?

 

[Ronsii]

I have had 78xx series regulators running in things for 20 years.... they will only burn out if they overheat... and they will only overheat if you draw more than the rated power. Do you know what the radio draws you are installing?

 

[Dickjr.]

Ronsii , I believe my radio draws about 6 amps max. The 78 I have is only good for one amp , it works you can't turn up the volume or the current goes flat. So I'm going to get one of the heavier converters for the power supply and leave the other 78 for the memory. I was told it would not work all together but it did.

 

[Ronsii]

Ronsii , I believe my radio draws about 6 amps max. The 78 I have is only good for one amp , it works you can't turn up the volume or the current goes flat. So I'm going to get one of the heavier converters for the power supply and leave the other 78 for the memory. I was told it would not work all together but it did.

Six amps!!! that radio takes some power I think all the 78xx are good for 1.5 amps(at least the TO220 case ones) but they are also limited by the power dissipation depending on how much voltage you are dropping so you could actually overheat without going over 1.5 amps depending on the input voltage.

I have also been told you can't run them in parallel... So I did... just made sure to use matched sets diodes and extra caps... works just fine

 

[Dickjr.]

The radio works , just when you crank it up it is starved for power and shuts down. I considered stacking about 5 of them together but I found a converter on ebay for 24$ that's 10 amp and has a year warranty. I took a heat sink out of a pc that was 4" x 3" x 3" tall fins all aluminum I figured if that didn't keep it cool nothing would. BTW I have a pile of those and other pc parts if you need something.

 

[caterpillarmech]

I swamped for my dad at 16 on the pipe line. Always had down time when he was running so I built him a jump box that I put a head unit, one or two speakers and 12' of leads. He would always go from dozer to excavator to a trencher so it had to be mobile. Now you just use an ipod or the like. Dad liked them and I liked having a project during the day.

 

[RobVG]

fee poops sake, the machine is set up for 12 volt accessories. ever notice the 12 volt power port behind the seat?

You were right edge. One of the sockets is 24 and the other is 12, probably to charge a phone. The boss said it has to be keyed because "someone" is leaving the radio on in his machine, killing the batteries. "They" also leave the door open and the radio gets wet so I'm putting in a marine stereo.

In my defense the EX's have a single 24v cig lighter. I also tried to test voltage at the sockets (yes, with the key on) and didn't get any. But there is at the connectors. Out comes the converter.

 

[RobVG]

Now what to do about the memory wire? In goes the converter...

 

[lantraxco]

I use this radio, couple different places to buy:

http://farmradiosupply.com/24_volt_radio.html

http://www.heavydutyradios.com/24_volt_stereo.html

Small, sealed, 12 or 24V, has RCA's on the back and a 3.5mm mini on the front for external audio sources. Pretty bulletproof.