.. 1. Mains sine wave (Green arrows show the zero crossing points). The Figure 1 shows the mains sinusoidal wave with the frequency of 50 Hz (sometimes 60 Hz). To build a dimmer, the zero crossing points (the points where the wave ...
.. of noise filtering and has negligible effect on the switching of Q 3 . You may need C 1 and R 5 to roll off Q 2 ’s frequency response to avoid the possibility of high-frequency oscillation. The transistor types are not critical; ...
.. determines the transmission power which of course affects the detection range. The potentiometer R5 adjust the frequency. If you have an oscilloscope, you should be able to see a signal like the Figure 4 at the U1, pin-3 ...
.. works. The R1C1 time constant couples the V IN /ppv square wave found at U1pin14 to U1pin9, creating an F PUMP oscillator frequency of (approximately): During the F PUMP negative half-cycle (U1pin4 = 0), the upper (U1pin14) end of C2 ...
.. the large-valued filter capacitors you usually find in a switching regulator, because there is no need to smooth out high-frequency ripple in the LED current. Common to all circuits is the option of adding a dimming capability by ...
.. recently purchased a new oscilloscope for home use. It’s a 250 MHz scope, but I was curious what the actual 3 dB frequency was as most scopes have a bit more upper end margin than their published rating. The signal generators ...
.. or bad contact). It also features a counter, which is very handy when you want to count impulses, to estimate the value of frequency or to test an interface. (This part is shown as a sketch.) The probe in Figure 1 consists of two ...
.. 1% “error” to result in a final, acceptably accurate 20 mV/ C demodulator output. The modulating/demodulating frequency F C generated by the A1b oscillator is deliberately set by the R4C1 time constant to be half the power ...
.. a cycle that begins with C2 being charged to V IN via U1a, then completes by partially discharging C2 into C3 via U1b. Pump frequency is roughly 100 kHz under control of the U1c Schmidt trigger style oscillator, so that a transfer occurs ...
.. output. A rather low value of inductance (0.1 1.0 mH) is sufficient. (This low value may be counter-intuitive to the low frequency of the multivibrator, which is less than 1 kHz.) The negative output voltage slowly increases with an ...