Xenon Circuits

This circuit will give provide a Good Strobe Effect for a variety of Portable Uses. Nominal current draw is "up to about" 1 amp at 12 volts. Depending on value of capacitor on pin 2 of the 555 and the particular choke that is used.

This circuit uses a small 2.5mm square photo diode in conjunction with a 100mH coil to detect the short light flashes from a xenon lamp. The coil makes the circuit immune to normal room lights. Its 10mv sensitivity can detect light flashes from a range of over 100 feet. Reflections from a room’s walls and ceiling is usually enough to trigger the circuit. The entire circuit draws only 3 Microamps from a 6 to 9 volt battery.

This line powered xenon flash circuit drives a small camera type flash tube. It has an optical isolator to allow the flash to be safely triggered from some remote device. A flash rate of 2Hz is possible with the circuit.

This is the matching transmitter for the air transparency monitor receiver. The transmitter launches powerful 1000-watt light pulses that last about 20 microseconds.

I designed this circuit many years ago to monitor the quality of a mile long column of air for future optical communications experiments. The transmitter system (circuit 72 below) uses a powerful xenon flash in conjunction with a large 12 inch fresnel lens at the transmitter end and a matching 12 inch lens with a PIN photo diode at the receiver. The receiver system was connected to a weather station and a computer to collect the changes in intensity of the light flashes under different weather conditions. It has the potential for a 30+ mile range. I have also used this system to conduct cloud bounce experiments.

This 9v battery powered circuit is designed for remote control flash needs. A charge control circuit turns off the high voltage generator when the photoflash capacitor is fully charged. A neon lamp is included to indicate when the system is ready to flash.

I designed this circuit many years ago to monitor the quality of a mile long column of air for future optical communications experiments. The transmitter system (circuit 72 below) uses a powerful xenon flash in conjunction with a large 12 inch fresnel lens at the transmitter end and a matching 12 inch lens with a PIN photo diode at the receiver. The receiver system was connected to a weather station and a computer to collect the changes in intensity of the light flashes under different weather conditions.

This circuit has a very low standby current requirement yet has very high sensitivity toward the light flashes from a xenon lamp. When connected to a flip/flop it can serve as an on on/off controller.

This 9v battery powered circuit is designed for remote control flash needs. A charge control circuit turns off the high voltage generator when the photoflash capacitor is fully charged. A neon lamp is included to indicate when the system is ready to flash.

This is the matching transmitter for the air transparency monitor receiver. The transmitter launches powerful 1000-watt light pulses that last about 20 microseconds.

This line powered xenon flash circuit drives a small camera type flash tube. It has an optical isolator to allow the flash to be safely triggered from some remote device. A flash rate of 2Hz is possible with the circuit.

This Adjustable Strobe Light is the bigger brother of the plain old strobe light. This one uses a much more powerful "horse shoe" Xenon tube which produces more light. You can also control the flash rate up to about 20Hz. Do not look directly at the flash tube when this thing is on! # T1 and L1 are available from The Electronics Goldmine (see Where To Get Parts). This ciruits is NOT isolated from ground. Use caution when operating without a case. A case is required for normal operation. Do not touch any part of the circuit with the case open or not installed. Most any diodes rated at greater then 250 volts at 1 amp can be used instead of the 1N4004's. Do not operate this circuit at high flash rates for more than about 30 seconds or else C1 and C2 will overheat and explode. There is no on/off switch in the schematic, but you can of course add one.

This DC-DC converter ("inverter") needs nothing but unmodified Radio Shack parts. You don't need to build or wind any coils or transformers. This is a cheap-and-dirty experimenter's circuit. I tested this and it worked for me, but I disclaim all warranties! The LM386 audio amplifier, R1 and R2, and C1 and C2 are used to make a crude Wien bridge oscillator. The R1-R2-C1-C2 network has minimum loss and no phase shift at approx. 3.5 kilohertz and serves as the positive feedback route for the oscillator. If an automatic gain/level control circuit was added to keep the oscillation from building up to the point that the LM386 clips, this circuit would be a sinewave oscillator. Instead, the oscillation rapidly builds up to where severe clipping occurs.

Figure 1 shows a complete circuit for an emergency lamp that operates from a 12V automotive battery. The xenon flash tube requires a 250V-dc anode voltage and a 4-kV trigger pulse. To generate the 250V dc, IC1, a switching regulator controller, and T1, a standard Versa-PAC transformer, operate in the discontinuous-flyback mode. With this configuration, circuit efficiency is typically 75 to 80%. R1 and IC1's internal-sense-threshold voltage limit the peak primary current to 1.6A. The R2/R3 divider and IC1's internal 1.25V reference at the VFB Pin determine the maximum-voltage setpoint. To generate the 4-kV trigger pulse, a standard cold-cathode- fluorescent-lamp (CCFL) backlight transformer, T2, operates in the forward mode. IC2, a dual MOSFET driver, functions as a 1-Hz oscillator and a one-shot for the trigger pulse for Q2.

The circuit of a battery operated portable miniature strobe light, which can be constructed using readily available inexpensive components, is described here. For convenience and simplicity, an ordinary neon lamp is used here in place of the conventional Xenon tube. The whole gadget can thus be easily accommodated in a small cabinet, such as a mains adaptor cover, with a suitable reflector for neon lamp to give a proper look. Since current requirement of this circuit is very small, it may be powered by two medium-size dry cells (3V) or Ni-Cd cells (2.4V). Transistors T1 and T2 in the circuit form a complimentary-pair amplifier.

Cell phones and PDAs are approaching the limit for small form factors, but their feature sets are growing with new functions such as built-in cameras and even video cameras. The initial in-phone cameras were basic, low resolution devices with little in the way of usable flash capability. However, cell phone camera resolutions have improved and sophisticated flash technology is expected to keep pace. There are two flash technologies used in digital still cameras. The first uses a Xenon flash lamp to provide a very short, high lumen flash with excellent spectral characteristics. LTC offers Xenon photoflash solutions that are simple, compact and efficient (see Design Note 345). The second flash technology uses LEDs.

This circuit uses a small 2.5mm square photo diode in conjunction with a 100mH coil to detect the short light flashes from a xenon lamp. The coil makes the circuit immune to normal room lights.

This DC-DC converter ("inverter") needs nothing but unmodified Radio Shack parts. You don't need to build or wind any coils or transformers. This is a cheap-and-dirty experimenter's circuit. I tested this and it worked for me, but I disclaim all warranties!

The MOSFET speed controller presented here took over six months to design and fully test, back around 1988. I designed it from the ground up, as I found there were no suitable circuits or units available anywhere at the time. Those that had been published before either required unobtainable servo chips, or were so unstable as to be useless. I took one designed by a British hobby magazine to a race meeting once. It had been okay around home, but the interference from other radio gear at the race meeting rendered it useless. It relied on "floating" a derived triangle wave between two comparators.

This discussion covers 3 different Xenon flashing circuits from disposable cameras. From them, you will learn circuit tricks that have NEVER been shown in any theory book. The first circuit covers 6 BUILDING BLOCKS. You will need an old "disposable Flash Camera" plus two extra parts to carry out the modifications.