Uwe Schüler is a retired electronics engineer. When he’s not busy with his grandchildren, he enjoys experimenting with DIY music electronics.
Uwe Schüler
Uwe Schüler
Areas of interest of the author: Oscillators Analogue Design Audio
Publications on RadioLocman by the author Uwe Schüler:
- 555 VCO revisitedIt is well known that a 555 timer in astable mode can be frequency modulated by applying a control voltage (CV) to pin 5. The schematic on the top of Figure 1 shows this classic 555 VCO. Modulating pin 5 has some severe drawbacks: The control voltage (CV)...Mar 13, 2026
- Wide-range tunable RC Schmitt trigger oscillatorIn this Design Idea (DI), the classic Schmitt-trigger-based RC oscillator is “hacked” and analyzed using the simulation software QSPICE (Ref. 1). You might reasonably ask why one would do this, given that countless such circuits reliably and unobtrusively...Mar 13, 2026
- Exponentially-controlled vactrolsBrief intro to vactrols Vactrols, or both an LED and a light depending resistor (LDR) (Ref. 1) in a light-tight housing, are found in analog music electronics circuits like audio compressors, voltage-controlled amplifiers (VCAs), voltage-controlled filters (VCFs), and other...Oct 22, 2025