A stroboscope is a device that produces short bursts of light with a high frequency. It allows you to view moving parts in detail without stopping them. Stroboscopes are electronic and mechanical.
Instructions
Step 1
Remember the main property of any stroboscope: the duration of the light pulse should be significantly less than the duration of the pause between them. Scientifically, this is called a large duty cycle, or, which is the same, a small fill factor. If this rule is not observed, a still image of a moving object obtained with a stroboscope will be indistinct, blurred.
Step 2
For a simple mechanical strobe, take a regular computer fan. It is better if it is of a large diameter - it is more convenient to work with it. Cut off the blades from its impeller. Glue a lightweight disc made of sturdy cardboard instead. It must be the same diameter as the impeller. the quality of adhesion should be so high that the disc does not come off the fan spindle during rotation. The disc should also be well centered. Turn on the fan and check that there is no vibration from the disc centering error.
Step 3
Turn off the fan. Carefully make several radial slits about three millimeters thick in the disc, for example with a model knife. Calculate the angle between the slots by dividing 360 by their number. Calculate the flash frequency at the rated fan speed using the following formula:
f = (ω / 60) * n, where f is the flash frequency, Hz, ω is the fan speed, rpm, n is the number of slots. For example, if the fan speed is 1500 rpm and there are four slots, the flash frequency will be:
f = (1500/60) * 4 = 100 Hz
Step 4
Pass light from any low-power, fireproof and directional light source through the slot. For example, an LED with a built-in lens will do. By using a resistor of such a value that the current through the LED is 20 mA, it can be powered from the same source as the fan.
Step 5
Turn on the fan and point it at an object that is rotating or moving cyclically. It will visually "stop". If not, adjust the flash rate. To do this, power the fan from a regulated source, while continuing to power the LED from an unregulated one. Do not exceed the fan's rated supply voltage. Remember that the object continues to move even though it is visually stopped. Don't try to touch him.
