0
\$\begingroup\$

The following circuit

circuit

has D1 which is a diode, and then D2 which I believe is another diode. I think that the diodes are there to simply act like a flood gate type thing where they are controlling and making sure the circuit does short circuit. Which would be the purpose of D1, but D2, I don't have an educated guess on it. What would their function be in this circuit?

\$\endgroup\$
  • 2
    \$\begingroup\$ That's the schematic of a microwave oven. 3 is the magnetron tube. 3 is a diode itself, D1 is an antiparallel diode to make the transformer deliver AC, thus avoiding saturation. D2 is a voltage limiter for C, as Tr and C are a series resonator. \$\endgroup\$ – Janka Nov 10 '16 at 0:08
  • \$\begingroup\$ Thanks. (Don't forget that can be answer @Janka) \$\endgroup\$ – EnlightenedFunky Nov 10 '16 at 0:27
2
\$\begingroup\$

That's the schematic of a microwave oven. 3 is the magnetron tube. It's anode is tied to GND. That's one of the rare cases where GND has a positive potential against other parts of the circuit. The mounting inside the oven is much simpler that way.

Because a magnetron tube is a diode itself, the circuit needs the antiparallel diode D1. A transformer has to deliver AC, it would saturate if there was a DC component. Instead of using a rectifier bridge, and instead of throwing away the energy of one half wave, the circuit also acts as a voltage-doubler. That's the purpose of C, which is a series resonator together with the secondary main winding of Tr. The purpose of D2 is limiting the voltage over C to avoid C fail miserably (it could explode on overvoltage.)

\$\endgroup\$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.