The circuit is activated by an LED/photoresistor isolator (Ul), which is a combination of a light-dependent resistor (LDR) and an LED in a single package. That device was chosen because of its high isolation (2000 V) characteristic, which is necessary because the strobe part of the circuit is directly connected to the ac line.The voltage divider is formed by R2, Ul`s internal resistance, and R3. When Ul`s internal LED is off, Ul`s internal LDR has a very high resistanceon the order of 10 . The voltage applied to NE1 is considerably below its ignition voltage of approximately 90 Vdc.The optoisolator`s internal LED is activated by a dc signal supplying 20 mA. The external sensor (s) that supply the signal are connected to the strobe part of the circuit at,11 and J2.
Click here to download the full size of the above Circuit.
When the internal LED lights, the LDR`s resistance decreases to around 5 kQ. Under that condition, about 125 Vdc is applied across CI, R4, and C2. The neon lamp periodically fires arid extinguishes as capacitor C3 charges through R4, and discharges via NE1 and the SCR gate.Resistor R4 restricts the current input to C3, and thereby controls the firing rate of NE1about three times per second. The discharge through NE1 is applied to the gate of SCR1.SCR1, a sensitive-gate unit, snaps on immediately when NE1 conducts, which completes ..the ground circuit for transformer T1 (a 4-kV trigger transformer). As SCR1 toggles on and off in time with the firing of NE1, capacitor C2 (connected in parallel with Tl`s primary) charges via Rl, and then discharges very rapidly through Tl`s primary winding. A voltage pulse is applied to the trigger input of FL1, a Xenon flash lamp.It is important to remember that the circuit is connected directly to the ac line. Resistor R6 is included to limit the amount of line current available to the circuit. The value of R6 can be decreased if you intend to modify the circuit for more flash power.Warning: Even though the circuit is fuse-protected, it can still be dangerous if handled carelessly.
This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of....
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is....
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to....
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This....
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the....
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound,....
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the....
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power....
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....
characters left: