Oh yes, had a 500w underwater light placed in a bucket of ice water for days while circuit was running, dimming from 0-100% brightness with no problem. The datasheets describes these "standard" triac with built in snubbers to handle phase control/light dimmer applications. I also have an...
Sorry for skipping right to the climax:
Load = incandescent bulb, 500W
voltage is 120VAC
triac is standard (designed for light dimmer), 8A rated, 600V
there is a snubber (0.1uF cap with 100ohmr resistor in series) across triac terminals
also there's an MOV across terminals
Gunnar,
are you saying that by pulsing the triac (opto) with a pw of 500us shouldn't kill the triac? THe load is a 500W, 120Vac incandescent bulb. SO for sure I am getting over the holding current. And I have verified on a scope looking at the triac trigger pulse width versus my zero cross...
I currently turn a triac on using an optocoupler MOC3052. I saw when writing the code that I need to pulse the MOC3052 optocoupler(from the microcontroller digital output)for a pulse width of 400-500us. I tried smaller pulse widths and couldn't get the triac to come on every zero crossing. Any...
HI All
I am using a zero cross detector chip placed at the front of my ac input connection, to detect AC voltage zero cross for phase control. I would think the RC snubber on the front end would delay the zero cross detection for every 1/2 cycle??
Maybe I could place a snubber circuit at the...
I currently have a 100 ohm and .1uF across the MT1 and MT2 terminals of the triac and currently have a flickering occurring. When I am connected to building power =no problem. WHen I am connected up to a generator that's when i get the problem. DO I know have sufficient snubber across the triac?
Conventionally I have always used a 1n4004 diode across a relay coil to prevent any back EMI. I have this solenoid application and was going to put diode across its coil. I have read previously that a fast recovery diode is recommended, rather thant the standard 1n4001-4004 series. Any thoughts...
Thanks for the replies. To start it's in existing design that I have inherited for some reason. I'm just looking for a fix in the field. If the design was preliminary (of course) standoffs would have been the obvious solution. Oh well. Thanks for the suggestions.
Hi Everyone. had a question. I have two pCbs mounted very closely to one another. I want to prevent from one board touching the other due to vibration, etc. Anyone know of any isolating material. I know I could conformal coat both boards, that might help. Maybe I could use a piece of neoprene or...
Itsmoked,
It is in a ROV. There are only three of these buggers inside a aluminum can, 10"ID x 12"L, filled with oil. In our tank the temp (in FLorida) is 80-90F, but the ROV will be stationed on a ship, with sea temps of 50-60F. oil is the best medium for transferring heat from an...
I got a basic question regarding power resistors. I know when specifying a power resistor, the power rating shall be twice the expected dissipated power. For example, I am using 3000 ohm, 10W resistor in a circuit application in which 120VAC will be across it. It is a nice power resistor from...
Itsmoked,
I am connecting an SMPS (AC-DC)to my triac circuit. There is no DC load connected. I measure the AC voltage out of my triac circuit (the AC input to the SMPS) and it reads ~120-135VAC. Now, the input to my triac circuit is 220VAC so when I digitally control my triac (not as a dimmer...
Didn't know this but now I do. SMPS require a minimal input current to operate? What I did was place a power resistor in parallel and the SMPS is working fine.
Cbarn that makes sense. The triac must see current in both directions to stay latched. I am using an opto-triac (MOC3052) to fire the 3 terminal Teccor triac. I would think there's a work around to use a triac to power up a SMPS. Could implement so some of filter on the front end o the SMPS...
Yeah the AC/DC power supply I am using does not have PFC. I am using a triac to drive the AC output with a RC snubber across the triac terminals. I am wondering if it is a charging/discharging issue. I am going to do some more probing with a scope. The input the DC power supply shall not read...
Yes, like I said I hook up an AC light to my circuit. I can control the light with no problem, there's 220VAC at the input of the light - no decrease in voltage. I hook up a AC/DC power supply (that has 220VAC input) thinking my circuit can drive it and the voltage decreases to almost half. The...
I have something I don't quite get. I have an AC circuit that controls an incandescent light. 220VAC as on/off switch - like an AC solid state relay. Works fine. Once I connect a switching power supply the AC output of my circuit drops the voltage down to nothing. I have no load on the switching...
NBU: THanks. Yeah reading through all the posts there are design parameters/consideration. The telemetry backbone is fiber optic and has no issues with ST connectors or CWDMS in oil. I have designed light controllers that operate 500W underwater incandescent lighting -no issues there. The older...
Many IC components have no issue in surviving very great depths. It's only the electromechanical relays, electrolytic capacitrs, crystal oscillators, anything with an air void in it.
