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 Description The heart of my flash trigger is an LM555 timer and a DM7473 flip-flop. The 555 provides an adjustable delay between an event being triggered and the flash being fired — for example, we want to wait for a falling drop to fall a few more inches before the flash goes off. The flip-flop triggers at the end of the delay and fires our flash. A circuit is required that would give a change in voltage when a light beam is interrupted. A phototransistor allows current to flow only when light is present. A large resistor between the phototransistor and ground causes 5V to be output when light is present, but pulls the output to ground when the beam is interrupted. Unfortunately, there’s bound to be ambient light hitting the phototransistor even when the LED beam is interrupted. The phototransistor may only reduce the voltage at its output by 1V when the beam is interrupted — we normally output 5V, and the 555 timer won’t trigger until the voltage dips below 1.67V, so the change ...

Hello! in this post I will show a very small circuit, the relay opens and closes its contacts intermittently, the speed can be changed by changing the value of C1, the output relay can be turned on an LED, working as a wink - wink! The relay coil and the capacitor voltage is in accordance with the circuit power!  See the figure below:

SSL3250A PHOTO FLASH LED DRIVER ELECTRONIC DIAGRAM These properties caused this device has long battery life and low power strain. Another features that this device has are protecting the battery and LED from overloading, trouble free operation such as overtemperature, over voltage, time-out function, undervoltage lockout, and feedback shorted protection.

Want to avoid the problem of carrying three different flashlights to perform a test? Why don’t you try integrating Ultra Violet, Infra Red and visible light together in one flashlight? Read on to know more about this. The multi-tasking flashlight is basically composed of a metallic case, a switch, cables and connections, four 9V batteries and three different LED heads that provide the desired light beam. For the construction of this flashlight, LedEngin’s LZ4-40 is recommended. This comes with a very wide wavelength that includes infra red and ultra violet light. Distinct visible light color temperature can also be found The first step is to build the body of the flashlight, using an aluminum tube. Next come the drilling and cutting for switches and covers. Once the body is finished, the work on the constant current driver should be completed, adding the proper terminals for the batteries and the base for the LED heads.  Once all the power source wiring is completed and insulated w...