We are looking to focus an IR laser on a phototransistor to use as a security device. As I understand it, the PT acts no different than any other transistor so the amount of IR it received should not be as much a problem as the load it is running? IE, how much can they handle without failure?
My thought was if they act as a transistor and if they conduct when exposed to IR, if the load through the transistor is limited, they should not fail?
For calculation example, I am looking at a 10mW laser, focused to an 8" spot at 500ft distance. That gives a watt density that is ridiculously small and might be very hard to see with a photocell. Like wise, a 250mW laser is just .77mW/cm
Are my calculations just off?
My thought was if they act as a transistor and if they conduct when exposed to IR, if the load through the transistor is limited, they should not fail?
For calculation example, I am looking at a 10mW laser, focused to an 8" spot at 500ft distance. That gives a watt density that is ridiculously small and might be very hard to see with a photocell. Like wise, a 250mW laser is just .77mW/cm
Are my calculations just off?
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