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Show us your square wave
Insatman:
sort of coaxial...it's a COTO 9000 series coaxial shielded relay. In the low voltage version the relay is soldered as close to the BNC connectors as I could manage. In the slightly slower high voltage version the relay is connected using a socket for easy replacement. This increases the inductance a bit.
When I swapped out the coaxial version for a non-coaxial version the rise-time did not change much as the ground is also carried across by my socket arrangement. I built the larger version with a socket so I could experiment with different relays. What I also found out is that over driving the relay coil helps with contact bounce.
I also found that these particular COTO relays can't handle the 1000kV charge voltage I was hoping to use. Still, 100V into 50ohms is more than enough for the work I am doing.
Insatman:
You can get a few 10's of Hz out of these relays. I set mine to run at single shot or ~10Hz switch selectable. I tested it up to 30Hz with no difficulties. COTO claims up to 1x10^9 operations, but I think switching 50ohm circuits will likely degrade this significantly. I have yet to wear one out however.
MrW0lf:
Keysight U1282A 2.4kHz, 50% duty into 600 ohms.
Otherwise nice but hydraulic press channel dude should deal with these parasitic spikes.
RedDogAlpha:
This is a great insight for someone green! Thanks for the post.
qu1j0t3:
1 kHz and 1 MHz generated by Arduino Duemilanove (program below); a little interference from 16MHz device clock is clear in the 1MHz trace. Rise/fall ~ 19ns.
Scopes: Tektronix TDS 460A (display in "High Res" mode) and HP 1741A (Conv mode).
--- Code: ---void setup() {
// for ~ 1 kHz output on PWM pin 9 (OC1A)
pinMode(9, OUTPUT);
TCCR1A = (1 << COM1A0); // toggle OC1A on compare match
TCCR1C = 0;
TCCR1B = (1 << CS12) | (1 << WGM12); // clkIO/256 prescaler; clear on timer compare
OCR1A = 30; // ~ 1 kHz
TIMSK1 = 0; //(1 << OCIE1A); // set output compare A match interrupt enable
// ~ 1 MHz on OC0A (digital pin 6)
pinMode(6, OUTPUT);
TCCR0A = (1 << COM0A0) | (1 << WGM01); // toggle OC0A on compare match; clear on timer compare
OCR0A = 7;
TCCR0B = (1 << CS00); // no prescaler
}
void loop() {
}
--- End code ---
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