The generated effect of strong flashes of white light is realized by super-bright LEDs, thanks to which the module can be powered by battery. The strobe lamp is easy to assemble and does not require any additional commissioning activities.
• Source of light – white, super bright LEDs.
• The light effect is selected by a switch.
• Adjustable frequency of light flashes.
• Low power consumption.
• Supply voltage: 4-6V DC.
• PCB dimension: 29×104mm.
• Electronic Kit – soldering required.
The schematic diagram of the strobe lamp is shown in Figure 1 in the user manual. The D11-D14 diodes are powered by current sources with transistors T2-T5. The amplitude of the pulses occurring on the basis of T1 transistor is limited to around 2V with diodes D8-D10. During operation, the sum of voltage drops on diodes D8 and D9 is similar to the sum of voltage UBE of transistor T1 and each of transistors T2-T5. As a result, at the time of the presence of a T1-based pulse, on each of the resistors R5-R8 there is a voltage of about 0.6V. This voltage is practically independent of the supply voltage, which means, that the current of the LEDs during the lighting does not depend on the supply voltage and it is approximately 0.6V/R5. For the given resistances R5-R8 the current of each diode is approximately 60mA. Four ultra-bright LEDs working with such a high current give a very strong flash of light, comparable to the flash of a typical stroboscope with a xenon lamp.
Usually white and blue LEDs have a conduction voltage greater than 3V, and at such a high current it can be higher than 3.5V. The resistors R5-R8 have a drop of 0.5-0.6V, and the saturation voltage of transistors T2-T5 can be smaller than 0.1V. As a result, the lamp achieves the set parameters at the supply voltage of 4.5V. To reduce saturation voltage and UBE voltage, BC338 transistors with maximum collector current of 1A were used.
Warning! The module should not be powered by a voltage higher than 6V!
Assembly and test
The assembly diagram of the strobe lamp is shown in Figure 2 in the user manual. The assembly is typical and should not cause problems. It starts with soldering resistors and it ends with soldering electrolytic capacitors, LED diodes, U1 socket, connectors and switch. The lamp works immediately after turning on the power. The frequency of strobe light flashes can be set using the PR1 potentiometer, and the light effect is controlled by the S1 switch. It is worth to check all 16 settings. The lamp can be supplied with voltage from 3.5V, but the optimal results are obtained with a supply voltage of 4.5-6V. The lamp can be powered from the power supply, but the low power consumption allows supply form battery, which increases the practical use of the stroboscope lamp. A set of four AA alkaline batteries is sufficient for several dozen hours of stroboscope operation.
R1, R2: 10kΩ
PR1: Trimmer potentiometer 100kΩ
T1-T5: BC337 or BC338
LD1-LD4: LED diode white
S1: DIP Switch
X1: 2-pin terminal block connector
Battery holder 4×AA (R6)