flash light help

Thread Starter

mavrick

Joined Dec 10, 2006
16
im trying to build a 28 volt light for hunting. i am wanting to wire a potentiometer switch on it to control the brightness level to conserve battery time. does anyone have any suggestions on the size of switch i would need. i also need some wiring help on how to wire it up. please help.
 

Papabravo

Joined Feb 24, 2006
14,412
ok here is what I would do: (mind you I'm really new to this stuff)



Its probably to simple to be what you want though.
Since the parallel combination of two resistances is lower then either of them won't you actually be draining the battery faster then just the potentiometer alone?
 

Thread Starter

mavrick

Joined Dec 10, 2006
16
well thats definitely not to simple because i dont have a clue.

is the thing at the top where the switch goes.

what does the squiggly lines mean.

i dont have the switch yet do you have any suggestions. i looked at some different ones. 10k, 50k 500k, i dont know what they mean.
 

Thread Starter

mavrick

Joined Dec 10, 2006
16
i just want a switch that will set the light as bright or dim as i want it.
make it as simple as possible. im very new to this and dont really know what im doing. any pointers would be appreciated.
 

TrevorP

Joined Dec 8, 2006
55
Basically: (if this circuit is the best option)

S1 is your power switch.
R1 is a variable resistor (depends on the Watt Rating of your light bulb)
L1 is the lightbulb
V1 is your collection of batteries.
 

Thread Starter

mavrick

Joined Dec 10, 2006
16
ok thats looking better. but the potentiometers i was looking at had like five different places on it to hook a wire. how do i wire it up.
 

TrevorP

Joined Dec 8, 2006
55
as far as i know you can get some potentiometers (that I think you are refering to) that physically stick while on the off mode (that is to say the circuit is incomplete)... and then when you turn them on you can adjust the resistance...

If that is the case then you don't even need that power switch.

That is all I know about potentiometers.
 

Thread Starter

mavrick

Joined Dec 10, 2006
16
how about wiring a 6 position switch to the batteries to make different levels of brightness. has any one got any suggestions on how to do this
 

Thread Starter

mavrick

Joined Dec 10, 2006
16
yes this is what i am wanting but i dont know how to wire it. the potentiometers i was looking at have 2 lugs on the bottom and 3 lugs on the side. the description was 10k potentiometer with switch.
 

wireaddict

Joined Nov 1, 2006
133
Let me offer a few pointers. First, I'd use a 100 ohm, 5-10 W rheostat. This can handle more current; most pots are 1 W or less. I don't think they ever incoroporate a built-in switch as pots do as an option. I'd use a switch in the light so the light & rheostat won't draw current when not in use. Some rheostats have 2 terminals instead of 3 where pots all have 3; if it has 3, the center terminal is the "wiper" or variable contact. Connect this terminal & one outside terminal so that the light gets brighter when you turn the rheostat shaft clockwise [with the shaft facing you]. [Connecting the third terminal is optional here.]

One final point here: you may find battery life disappointingly short [unless they're size "C" or "D"] & the the replacement cost for 24 batteries excessively high.
 

Thread Starter

mavrick

Joined Dec 10, 2006
16
thanks for the pointers dave. the light its self has rechargable batteries and they are 24 1.2 volt -28.8 volts total. i would like to get the on and off switch and brightness control together if at all possible. if i didnt use the rheostat. would the potentiometer with on and off switch hook up the same way.
 

Chris Wright

Joined Jul 26, 2006
62
im trying to build a 28 volt light for hunting. i am wanting to wire a potentiometer switch on it to control the brightness level to conserve battery time. does anyone have any suggestions on the size of switch i would need. i also need some wiring help on how to wire it up. please help.
Why are you using 28 volts?
 

Gadget

Joined Jan 10, 2006
614
I know you dont want to hear this cause it's only simple, not Simple simple, but the best option is to use a 555 timer to generate a square wave, with a potentiometer adjusting the Mark Space ratio. Use that to drive a MOSFET or even a transistor. This will vary the brightness without loosing a lot of power to heating up the High Power potentiometer you would otherwise have to use.
I have used this setup very successfully with a 12volt spotlight for Bunnie Hunting.

A simple simple method would be to use mutilple bulbs... say 1 watt, 5watt and 15 watt.... and switch them in single or multiple configurations. No power wasted then.
Only draw back is all 3 bulbs couldn't be at the focal point of the reflector.
 
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