Stepping Down 12-VDC to 10-VDC

From one Arkie to another, at 9V it'll be 90% as bright and degrade at 90% of the 10V rate.

It's in the pool room, after the second beer who gives a sh$t.

And finally, I'd stay away from any stepdowns in the pool room, as they can increase the trip potential. Especially after the fourth beer.

Hey Lyn, the wife said it looks fine at 90% with the 9V, so we are good. Now that I know it want be hurting my hard to fine light bulbs for it, all will be good.

Hey just a note about Oaklawn; We set up a moblie cow (AT&T Wireless Cell Base) today to handle the crowds phone calls during the races that will be taking place over the coming weeks. With 3G now in Hot Springs there is not enough room for everyone.

jhunter

I would have found a way to get back there for the Apple Blossom if both the girls had been able to run.

See ya.

10 VOLTS looks a bit strange to me. Probably it will work @ 12 V too but how long? If it is really a special voltage light you can bring it to that level, with a resistor, a power transistor, or thyristor that dissipate the power, created with the 2 volts difference. All these things become warm to hot and need efficient cooling. You didn't specify the wattage of the lamp, so we can't tell how much the components need to dissipate. The other way is to chop the battery voltage, so that the avg. time the light is on is only (10/12).10 th of the time is on. This chopper has to work at a frequency above 26 Hz to avoid visible "flickering" of the light.

The voltage drop of the DC run from the resistance in the wire might give a drop of 2 volts to 10 volts from 12vdc power source. Like the gentlemen above said, after a few beers who cares

Take a very thick copper wire with the battery in LA and the light in NY.

At 9 Volts it is going to consume 81% of the rated power, means brightness is going to be about 81% of the brightness that is observed at 10volts,

(9/10 x 9/10)x 100= 81%

OK, 81%

81% it is then. When we look at it now we really don't see it much dimmer at all, with all the other lighting around.

Hey and at this point as stated earlier it looks great. LoL.

jhunter

Probably that's due to efficiency factor. In another words that added one volts is converting in heat and not in light.

In that case it is better to operate it at 9 Volts.

Better run if off through 9V than 12V. The higher the voltage the lesser the life of the bulb. On the other hand the lower the voltage the lesser the light output but increase life expectancy to the bulb.

-Joey

Thanks, I will stay with the 9V since it is doing fine.

jhunter

Do not be too disappointed by 81%; in fact it is somewhere between 81% and 90% because the resistant of filament changes with voltage (or better with temperature that depends on voltage). The lower the voltage -- the lower temperature, consequently, the current will not drop proportionally to voltage but a little bit less, and power will not drop in square to voltage drop. I am glad that 9 volts work for you... By the way, after which beer it started looking good?

Hey Guys:

In the 12 volt system in most cars the voltage supplied by the altinator is actually 14 1/2 volts when the engine is running and that dosent affect the bulbs or the electronics, even though I have never herd of a 10 volt system would 12 volts really make a difference?????

Michael.

There is a voltage regulator in your car. Bulbs are designed for 15VDC, maximum but selected to provide the desired luminescence at 12VDC, so there is always a tolerance. Incandescent lights function by a glowing wire (filament) that is a resistance drop that glows white hot. Increase the voltage across the resistor and what do you get? More wattage. More wattage means more heat. In electrical components, a general rule to all things is that failure = heat x time. More heat, faster failure.

If you want a self contained light without a power cord, you might think about replacing the 10 volt power hungry bulb with an LED and appropriate battery. Your light will last much longer between refills.

There is no way to change this other than dropping my 10DC to9DC if I am to keep the antique RR light original. The only bulbs that fit these are a special made 10DC bulbs.

jhunter

At Digikey, for $2.28 you can get:

TLE4274G V10

a voltage regulator that gives you a 400mA output @10V. It can be supplied from 10.5V to 40V.