Many have already appreciated the convenience of using motion sensors in their home - the light automatically turns on when you enter the room, various equipment. Many people strive to assemble such a sensor with their own hands in the hope of saving money. Not the easiest solution, but quite possible.
It is necessary
FD 265 photodiode, RES55A relay, transistors, resistors, 5V power supply, voltmeter, soldering iron, wires, laser pointer, water gasket, screw
Instructions
Step 1
The first stage of work is to prepare the power supply for the sensor, which will work continuously by default. To do this, take a power supply, cut off the connector from it and determine where the plus and minus are located using a voltmeter.
Step 2
Solder a 10K resistor to the plus.
Step 3
A photodiode with a cathode should be soldered to a resistor soldered to positive.
Step 4
The anode of the photodiode is connected by soldering to a so-called trimming resistor. The emitter of the transistor is soldered to its minus, and the collector is connected to the base VT1, soldered to R1.
Step 5
Next, the following elements are connected: the emitter VT2 with a minus, the contact of the relay with the collector VT2. The other contact of the relay is soldered together with the "plus" of the power supply.
Step 6
Since the sensor is easiest to organize on the basis of a laser pointer, the next stage of work will be to create one. In general, the same power supply will do. To do this, two more wires should be soldered in the block in parallel with the existing ones.
Step 7
Take the screw, insert it into the plumbing gasket and all together, with the head inward, insert it into the pointer - the screw head should rest against the spring inside.
Step 8
Now connect the wire from the power supply to the screw, and slide the other between the pointer body and the gasket.
