Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.
I want to generate an ac signal 300Vp-p Which is added with a dc voltage (0-20 V) With a maximum current of 4 amps.
Nobody has an idea for the circuit.
Two (isolated) power sources, one AC, maybe with a transformer and a DC source connected in series.
But mind:
* the DC source need to be able to source and sink current. (At least sink into a big capacitor)
* and the AC source need to be able withstand DC current...so a standard transformer will be critical.
Suppose you start with bipolar DC supplies, +330V -330V, to power a half-bridge. Then raise or lower bias voltages to obtain desired AC output at the load. (The bias signal needs to sink and source 12 W peaks.)
By placing NPN at top, it avoids shoot-through and power loss. Positive output matches (follows) bias voltage to the NPN.
Negative output matches (follows) bias voltage to the PNP.
This arrangement is efficient if your signal is a square wave. Or else you can preserve efficiency if you apply bias as PWM. In other words create class D operation (per post #3).
Two (isolated) power sources, one AC, maybe with a transformer and a DC source connected in series.
But mind:
* the DC source need to be able to source and sink current. (At least sink into a big capacitor)
* and the AC source need to be able withstand DC current...so a standard transformer will be critical.
if the DC voltage in series has to act like a large battery ( i.e. source & sink power ) then it would be more ideal to have an active electronic load ( could be a lash up ) to absorb power above the output voltage of the buck converter, this could be as simple as a TL431 controlling a large P fet or xtor - which would allow it to be adjustable ....
Either that or a fully active buck ( synch buck fet rather than diode ) fed from a supply that also has an active load on it - this works because the buck is now bi-directional ...
You didn't yet tell what the AC source is - a mains transformer or an artificial source. In the latter case, I would consider to generate the whole combined signal at once by a four quadrant pwm source.
Bidirectional (regenerative) DC sources are e.g. made for battery testing, but are not so common yet. The AC current through the DC source can be buffered by a big capacitor. If there's still an average DC current to be sink by the source, a ballast resistor in combination with a regular (single quadrant) DC source might do the job.
I want to generate an ac signal 300Vp-p Which is added with a dc voltage (0-20 V) With a maximum current of 4 amps.
Nobody has an idea for the circuit.
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.
