These bulbs are rated 200 mA at 7.5 volts.
_ If _ W = A * V, then W = 1.5A when .2A * 7.5V
The 12v bulbs I removed had markings of 2.2 and 3.0 W.
IF my formula for W = AV is correct, then there isn't much difference in
current.
Someone who knows electric theory is invited to participate in this.
Electricity is not my first love, and I'm trying to perfect a hydraulic
lightbulb to get away from the stuff entirely.
Bob
On Fri, 21 Nov 1997 18:59:22 +0000 Paul Hunt <paul.hunt1@virgin.net>
writes:
>ROBERT G. HOWARD wrote:
>>
>> They won't burn out immediately, if that's a concern; at least
>they
>> didn't when I turned them on. They seem to be able to take the
>> overvoltage long enough for you to realise that you don't want them
>that
>> bright. When you turn them down to a reasonable level, they're
>probably
>> getting less than 10v anyway. Since they were rated for 1000 hours,
>if
>> you get 1/10 of that you still have 100 hours, and that's more than
>3000
>> miles at 30 mph.
>> As to the list of things to take in your MGB spares kit for a 3000
>mi
>> trip--guess we don't need to take spare instrument lightbulbs...
>> Bob
>>
>> On Thu, 20 Nov 1997 08:05:43 -0600 "Feldman, Jack (Jack)"
>> <jack@lucent.com> writes:
>> >Bob,
>> >Your message implies that you have turned to the rheostat to the
>full
>> >14.4 volts without burning out the light bulbs. Can they really
>take
>> >the
>> >over voltage, or will they burn out immediately if one is not
>careful?
>> >
>> >Jack
>> >
>
>What (or should that be 'watt') is the wattage of these bulbs? In my
>experience the
>rheostats burn out at a point just before maximum brightness.
>Although the resitive
>track in the rheostat is at its widest at this point, the power
>dissipated seems too
>much for it, and I am wondering how the current with with 7.5v bulbs
>compares,
>particularly if one has extra gauges on the circuit.
>
>PaulH.
>
>
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