.. 1. Variable AC power control with a simple pushbutton. When S1 is pushed, counter U1 ramps through the 64 DAC codes in a 2 10 /120Hz = 8.5-second cycle and stops on any selected power setting when S1 is released. Power control method The power ...
.. frequency from 2 MHz to 1 MHz to allow for the 75-ns minimum off time. This would also require increasing L1 to about 10 µH to 15 µH and doubling up on bulk-output capacitor C4 to maintain equivalent performance. References ...
.. was to amplitude-modulate the power output stage of an infrasonic microphone ( Ref. 2 )That gadget generated both the sub-10 Hz baseband signal and an audio tone whose pitch varied linearly with it, allowing one to hear at least a proxy for ...
LEDs need current to illuminate, and current usually flows through a power supply to an LED. A typical LED-driver circuit uses a transistor to provide current and a series resistor to decrease the voltage you apply to the LED. Unfortunately, the ...
.. the mismatch between test parts A and B. The resulting difference signal is boosted by preamp A1d in switchable gains of 1, 10, or 100, synchronously demodulated by U1a, then filtered to DC with a final calibrating gain of 16x by A1c. The key ...
.. I expect it to operate at the lower frequencies at least as well as Woodward’s circuits. Operation down to 1 Hz or 10 Hz is, in my opinion, mostly for bragging rights, and I am not concerned about that. I expect this VFC to be useful ...
We’ve seen lots of interesting conversations and Design Idea (DI) collaboration devising circuits for power switching using inexpensive (and cute!) momentary-contact SPST pushbuttons. A recent and interesting extension of this theme by ...
.. NPO/COG capacitors and the resistors of the values and tolerances shown in the schematic are available for well under $0.10 in 1000-piece quantities. The filter shown is a 3 rd -order one (evident from the presence of three capacitors). ...
.. instantaneous 60-Hz half-wave polarity. The type H11D1 300-V opto has a typical current transfer ratio of 80% which makes ~10 mA of PWM drive current necessary. Current limiter R2’s 330 Ω assumes a 5-V rail and a low impedance driver. ...
.. 1a's circuit without using additional compensation circuitry (Figure 2). For a 2400 bps serial link with less than 10% error on the bit length, the rise-time estimate is 42 µsec, which corresponds to a 7.5-kilohms resistor. ...