Peak crossing switch......
开云体育For product testing/approval I did a circuit years ago that allowed me in software to turn it on at any point. Basically, an opto to get line sync, a variable delay and a heavy-duty relay.? The software compensated for the relay delay. It also had a random mode and controlled duration glitches. I will upload the sync pulse generator. ? Capacitor current: If you connect a capacitor to a voltage source the capacitor will charge to that voltage.? There will always be some series resistance. The current vs time of course follows the RC charging curve. The starting current is only limited by the series resistance in the circuit.? Regardless of capacitor value. How long the pulse is depends on the capacitance. In the example with 150V and 100 Ohm you would get 1.5A, If 10 Ohm, 15A. I have a feeling that I am writing stuff that you obviously know.? Just forget about AC and rewind to electronics 101 ? ? From: [email protected] <[email protected]> On Behalf Of wn4isx via groups.io
Sent: 20 December, 2024 19:03 To: [email protected] Subject: [electronics101] Peak crossing switch...... ? Does anyone have any idea how difficult it is to arrange a circuit to apply power to a DUT (Device Under Test) only at peak voltage? On both halfs of the 60Hz waveform? ? It is an imperial PITA on steroids! ? I went with a NE555 triggered at the zero crossing point and timed half way from that point for peak voltage. ? Simple zero crossing pulse generator to start the NE555 cycle. ? I used a 4N27, the output transistor drove another transistor, Darlington configuration. This drove a 600V 6Amp?Triac?by Teccor Part# Q6006F52. ? I used a 300 ohm 100 watt resistor (I have all sorts of odd stuff) as the load to insure the TRIAC would turn on and off. The turn on and off was OK but the timing was anything but OK. ? The output drifted around the peak but never was remotely stable. ? I was ready to give up when a friend said "Terry just use a 2 wire light dimmer module, they'll let you set for peak and hold it. ? My friend brought over several Hubble dimmer and, after some rewiring, I have a peak current turn on power supply. ? Note: Use a dimmer with dual RC network for increased stability. ? ? Now tomorrow or Sunday or Monday or someday really soon now I'll check the peak current through a 0.5uF capacitor. ? Now the real question, will a Siglent SDS 1202X-E capture the transients as the capacitor charges from the rapid delta-V? ? [Damn I wish this font had Greek characters!] |
开云体育If we arbitrary guess on a total series resistance of 100 Ohm and 0.5?F and 150V, you ought to see a peak current of 1.5A and an RC pulse duration of 50 ?seconds. ? To make the setup much easier and safer, I would use a DC power supply. Bertho ? ? From: [email protected] <[email protected]> On Behalf Of wn4isx via groups.io
Sent: 20 December, 2024 21:22 To: [email protected] Subject: Re: [electronics101] Peak crossing switch...... ? The series resistance will be the AC Mains wiring and triac. The resistor goes from the triac to neutral to insure the triac behaves. There is also a 1M resistor across the 0.5uF capacitor and a push to fire switch. ? Do you believe a Siglent SDS 1202X-E can capture the transient. ? BTW. I've already added the resistor to the LED tube circuit. ? |
开云体育Hi Mikek, I am sorry for your headaches. The symbol shows up fine on Windows, even on the received email.? I typed “Alt +230” for the Greek micro symbol. I am curious what system you are using.? Also, your symbols are displaying OK on the email. Bertho ? From: [email protected] <[email protected]> On Behalf Of Mikek
Sent: 21 December, 2024 9:07 To: [email protected] Subject: Re: [electronics101] Peak crossing switch...... ? On Fri, Dec 20, 2024 at 04:03 PM, wn4isx wrote:
Do you mean this ▲ (hold alt while typing 30) or this δ (hold alt while typing 235)?? AKA, alt +30 and alt+235 Ω = alt+234, ? = alt+230,? π = alt+227?? β = 6Alt+225 ??????????? Mikek ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? |
Bertho