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BreedJ 1 hour ago
The purpose of D1 is to prevent that the C35 will not dischange through pin 15 after pin 15 is 0V again. Its a schottkey diode because it has to switch fast and must have as little voltage drop as possible. D2 and R12 together form a current source. That will result in a lineair voltage rise over C35 since the current will not change when the voltage over C35 is rising. Without D2 the voltage will rise exponentially. But then it will be more difficult to calculate the phase shift.
GPS assisted 10 MHz frequency reference
Jerome Odier
Jerome Odier 3 hours ago
I see that you use the 3rd phase comparator (PC3, pin 15) of IC2 (4046) but I don't understand D1 and D2 in the "V-PLL" filter stage. Thanks
GPS assisted 10 MHz frequency reference
magicChristian 16 hours ago
Hi Dany,  now I found time and changed the circuit to what I wanted.  I also simulated in LTSpice and it looks good. Maybe the dimension can be optimized.
230V AC dimmer, mains isolated, using P12F629
Calpe 16 hours ago
For those choosing to build two amps, the question comes as to what Power Supply to use. Several comments have been made in this project whether to use 55v or to get max. output from the amp, peak power etc etc. My question raises the question if two single power supplies should or can be used or just to use one single higher rated PSU. For two single PSU's then the Connexelectronic SMPS500R can be used. These are capable of delivering 500W continuous and 650W peak power. The cost each would be $82, plus postage. However, the SMPS800RE are capable of delivering 800W continuous and 1000W peak power, and are priced at $112. Logically, it makes sense to use one single PSU. My question lies as to whether there might be any complications using one single PSU? Some technical expertise would be appreciate before ordering the final components and switching on. 
Q-Watt - Simple Audio Power Amplifier (110656)
sequencer 19 hours ago
After the PCBs arrived I've mounted a first unit and performed some basic tests.  At the initial trials I had some troubles keeping under control the 200GHz gain-bandwidth product of the TL3116. I achieved it with a little of positive feedback (that's what all we need). Now I'd say the main goals are fulfilled.   Fully differential, compact design (100x56mm PCB). Low-cost, easy to find components. Can be supplied directly from the secondary of a mains transformer (18V AC max), or from a DC power supply. Differential gain: 26 dB Current consumption at rest: approx. 48mA at 24 Vdc supply (1.1W) approx. 37mA at 12 Vdc supply (0.44W) Modulating PWM frequency: approx. 650kHz DC voltage at output: < 10mV Bandwidth: 10Hz .. 20kHz -2dB THD+N at 24Vdc supply and 8Ω load (low-cost inductors and bulk capacitors): < 0.04% at 1W output < 0.06% at 10W output < 0.5% at 30W output SNR max. (10 W output): > 82dB During the next days I'm going to take more measurements and try tuning on some component values. Then I'll post the complete design with files and graphs. Thank you.