开云体育

Ok, about the relay first, You will realize that it is a latching relay with a single coil. So?

1. if there is no current through it, it stays in whichever state it is (on or off)
2. If you pump current in one direction through the coil it gets latched on. If you remove the current the relay continues to remain on.
3. If you pump the current in the other direction through the coil, the latch comes off, if you remove the current the relay continues to be off

This kind of relay usually needs?an ability to swing voltage on both sides of the latch to?pass current in both directions.?

In this genius work, There is a capacitor at one end of the relay (lets call that end of the latching coil as A). Let's imagine that the?capacitor is discharged and the other end of the coild?(Let's say B) is also low. Nothing happens.

Next, the B end is pull high (like a regular relay). The capacitor being dischraged?allows the current to flow from B->A , latching the relay on. The capacitor eventually charges to the high voltage and no more current flows through the relay.?

Now, when the B end is pulled down, the capacitor at A end of the relay coil discharges, reversing the current flow, turning the relay off, the current continues to flow until the capacitor is discharged, then no more current flows!

About the driver amplifier,

it provides 20 db gain without a trifilar transformer. This works even with the 2N2222 all the way to 14 MHz. Of course, the 2N2222 won't handle this large a current. We have used this in the zbitx.

- f