Setting and clearing multiple register bits
Setting bits ```REG |= (1< for example:…
A series of analog waveform generator designs
Overview Each of these designs use a TC4667 charge pump to create a negative voltage from a +9VDC supply. DC offset adjustment of the AC output signal is attained via the +/- voltage divider OFFSET potentiometer. This is summed along with the generated waveform. The amplitude of the output waveform is determined by the feedback…
Balancing non-inverting opamp gain to minimize distortion
The Experiment Here is a common dual opamp configuration: U1A is an attenuator configuration while U1B is a positive gain configuration. Here R3 is just a resistor to ground, but in practice R3 might represent a sub-circuit consisting of an active filter. What is the relationship between the two opamps regarding their gain and distortion…
555 Timer cheatsheet
Here's is a quick visual guide to illustrate how the trigger and threshold pins can affect the output of this timer IC chip. Trigger active Here the signal sent to the trigger is less than 1/3 of the supply voltage (VCC). The output is 1. The discharge transistor is disabled. Threshold active Here the signal…
Why don't you get "tone suck" from a long speaker cable?
In a word, impedance. The source impedance from your instrument/amplifier signal, coupled with the capacitance of the cable, creates a low pass filter. The makeup of a standard shielded, unbalanced cable matches that of a capacitor Any signal at a frequency above the cutoff will be attenuated by 1/3 relative to the input signal voltage…
Not another MC34063 switch mode power supply....?!
Ever needed a negative voltage rail to quickly test something on the bread board? Look no further. - Abstract: This design uses the "classic" MC34063 switching regulator IC to invert the input voltage rail to a negative voltage, simultaneously stepping up/down the output depending on the position of the rotary dip switch. The resistors in…
AC Theory Cheatsheet
Inductance is the relationship between the current and the magnetic field generated in a coil. Each is proportional to the delta of the other. L = l + 0.45 d d 2 n 2 d is diameter of coil in meters, n is number of coil turns, l is length of coil in meters…