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Electrical Question: "Voltage Tap"
Posted: Sun Apr 11, 2010 11:06 am
by mark.f
Do you think the below method would work for supplying 1.5 volts to an electronic igniter using a 12v battery pack? It'd be kind of hard to determine running resistance of the igniter, so I don't think a resistor as a voltage divider is practical...
Posted: Sun Apr 11, 2010 12:38 pm
by Technician1002
An electric igniter is a dynamic load (current varies in normal operation). You will be best to use a battery.
Posted: Sun Apr 11, 2010 12:53 pm
by geardog32
whats the impedance of the fan? and whats wrong with just using a 1.5 volt battery for the igniter and separate battery for the fan you already have two switches and this would be simpler and less loss through a bunch of resistors trying to get down to 1.5 volts.
Posted: Sun Apr 11, 2010 1:29 pm
by Bluetooth
geardog32 wrote:whats the impedance of the fan? and whats wrong with just using a 1.5 volt battery for the igniter and separate battery for the fan you already have two switches and this would be simpler and less loss through a bunch of resistors trying to get down to 1.5 volts.
Who said anything about a fan?
Posted: Sun Apr 11, 2010 4:42 pm
by jimmy101
I wouldn't bother with a resistor in series with the igniter. To actually drop 12V to 1.5V the resistor will have to dissipate 8 times as much energy as the igniter itself.
What is the circle with "BBQ" in it?
You can tap from the individual batteries in a battery pack. You have to be careful that you don't exhaust that battery much quicker than the others in the pack.
Posted: Sun Apr 11, 2010 7:07 pm
by geardog32
Bluetooth wrote:geardog32 wrote:whats the impedance of the fan? and whats wrong with just using a 1.5 volt battery for the igniter and separate battery for the fan you already have two switches and this would be simpler and less loss through a bunch of resistors trying to get down to 1.5 volts.
Who said anything about a fan?
there is clearly a fan in the diagram
Posted: Sun Apr 11, 2010 8:53 pm
by mark.f
Whoah, I guess I need to explain.
The upper left portion of my diagram is exactly what jimmy101 posted. The circle with the BBQ in it is an electronic BBQ igniter (hacked down to fit in a project box instead of using the built in batter holder/switch). Sorry for my unconventional wiring diagram (and unwillingless to crop out the irrelevant part of the circuit.
)
That answered my question, though. Thanks jimmy.