Switch 3A with a small reed switch

Hi there, I'm wanting to switch around 3A using a reed switch (eg

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with the aim of driving a SSC P7 LED. Source voltage will be be around 3.7v (Li-ion) and the max current through the LED will be 2.8A.

Could I use this MOSFET (BUZ-71 Sipmos Power FET) to achieve this? My understanding of electronics is basic, so if you could provide a circuit/guidance it would be much appreciated.

Thanks in advance

Reply to
jmunrohill
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:Hi there, :I'm wanting to switch around 3A using a reed switch (eg :

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with the :aim of driving a SSC P7 LED. :Source voltage will be be around 3.7v (Li-ion) and the max current :through the LED will be 2.8A.

: :Could I use this MOSFET (BUZ-71 Sipmos Power FET) to achieve this? My :understanding of electronics is basic, so if you could provide a :circuit/guidance it would be much appreciated. : :Thanks in advance

Data for your LED

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I would suggest you do some searching driving high power leds. For example

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Since you are not an experienced electronics constructor I would suggest you stick to the simpler constant current drivers to start with.

Reply to
Ross Herbert

example

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Thanks, I've got the driver sorted, but there is still 2.8A going through the inputs of the driver, therefore I can't switch it with a small reed switch (hence either using a relay or a mosfet).

Reply to
Jason

"Jason"

** Is there no shut down pin or other way to turn it off ?
** Reed switches exist that will do your job:

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..... Phil

Reply to
Phil Allison

:On Aug 6, 4:31 pm, Ross Herbert wrote: :> On Tue, 5 Aug 2008 19:20:51 -0700 (PDT), snipped-for-privacy@gmail.com wrote: :>

:> :Hi there, :> :I'm wanting to switch around 3A using a reed switch (eg :> :

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with the :> :aim of driving a SSC P7 LED. :> :Source voltage will be be around 3.7v (Li-ion) and the max current :> :through the LED will be 2.8A. :>

:> : :> :Could I use this MOSFET (BUZ-71 Sipmos Power FET) to achieve this? My :> :understanding of electronics is basic, so if you could provide a :> :circuit/guidance it would be much appreciated. :> : :> :Thanks in advance :>

:> Data for your LED

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:>

:> I would suggest you do some searching driving high power leds. For example

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:>

:> Since you are not an experienced electronics constructor I would suggest you :> stick to the simpler constant current drivers to start with. : :Thanks, :I've got the driver sorted, but there is still 2.8A going through the :inputs of the driver, therefore I can't switch it with a small reed :switch (hence either using a relay or a mosfet).

If you are using the reed contact correctly it will only be passing minute current to switch the fet on. The fet will be handling the heavy current.

I would experiment with the circuit shown in Step 8 in the link I gave above with the reed switch in series with the resistor and zener diode. Forget the PWM uC part.

For normal operation you would be driving the led at around 1.4A.

Reply to
Ross Herbert

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