Buck-boost converters – I am designing a buck-boost circuit but the values of the L, R, and C are hard to get. Anybody have an equation for this? My project has a variable input from 6 to 20 V and a 12-V output. Read more.
Need help with circuit design – I need a relay circuit with an output of 12 V. The relay must be activated by a button and run for a duration of time that is set with a knob/trimmer. Times only need to be adjustable from 1-20 seconds roughly. When the timed circuit ends, it should not start again until the button is pushed. It would be nice to actuate a red LED when off and a green LED when running. I know this is probably already built somewhere but I do not know how to find such a thing. Read more.
Analog voltage detector – I am looking for circuit that is able to detect voltage changes without help from chips. Let’s say I want to turn on diodes based on the magnitude of a voltage – if voltage is low, just one of four diodes is on. With the help of a microcontroller and an ADC this is simple. Can it be done without a micro… ?
Capacitor frequency range – I want to design an analog circuit which works at 10-100 MHz. I need input/output caps to block DC current. What should the value of the caps be? Can I use a 1 nF cap? If not, what value do you suggest? Please give me some advice.
Common-emitter amplifier is asymmetrical – I tried to design a simple CE amplifier but I found it amplifies the positive half cycles more than negative ones !!! What could possibly cause this error?
The gain is supposed to be 20. ….When is the input voltage is larger than 0.5 mV the amplifier starts to become asymmetrical.