Many thanks
@hdmunger for all the guidance. I’m sort of up and running lol.…unautomated. I have a light switch to turn the ZVS on/off and I can get a 6 CM case glowing in 4-5 seconds. Sestos timer still on a slow boat from somewhere unknown. Maybe the remaining steps will make more sense when I have the timer. But I’m still struggling conceptually with the relay and timer integration. Specifically, how do you input 48v into the relay and get 48v out to the ZVS? I hooked up the relay but don’t seem to get the correct outputs with a voltmeter.
Okay, here is a simplified schematic of the electrical part of my build:
First, you have to think of a relay as having 2 modes (upper right corner). The first mode is when it is unpowered, and the input signal/current is going into the common (center) contact. That contact is NOT connected to the NO (normally open) contact, but IS connected to the NC (normally closed) contact. When the relay is activated, The NO contact connects with the Common contact and the NC contact disconnects.
The normal use for the relay is to connect the Common input to the NO output when the relay activates. An alternate use is to use the NC output and the Common input to switch something OFF when the relay is activated and the normally closed contact opens.
The big relay used to switch the ZVS board on and off, in my build/schematic, has 2 internal relays running in parallel to connect/disconnect both the 48V+ and 48V- wires.
A normal relay usually has 5 contacts, V+, V-, NO, Comm, NC...where V+ and V- control the internal switch and the internal switch controls whether the Common contact is connected to NO or NC. The big relay I use has an additional set of NO, Comm, and NC contacts for a second internal switch that runs in parallel to other...both are either ON or OFF.
Power Sources:
- The 48V DC power supply and the Sestos timer both run on 110V AC
- The big relay is
controlled by 12V DC from whatever source you have (separate power supply, buck converter, whatever) and is used to switch on and off the 48V DC from the power supply to the ZVS board
- The ZVS board is the only use of the 48V DC output from the power supply (generally)
Going back to the earlier discussion of the the Sestos timer, it has 4 timers that run consecutively, one after another. Timers A and C each have an internal relay that is activated while that timer is running. The A timer/relay is generally used to switch on the ZVS board for the length of time timer A is running. The C timer/relay is used to activate the drop solenoid while it is running...generally for a very short duration of about 1/2 second. Both of those instances use the NO contact to turn on the component they control, when activated.
So, to make a long story longer, here is a step-by-step progression of the normal timer cycle:
- press Start button for the timer to begin
- timer A runs, its relay closes, which closes the big relay and the 48V supply is connected to the ZVS board
- timer A ends, its relay opens, which opens the big relay and the ZVS board is powered down
- timer B runs, generally set to 0 seconds because nothing needs waiting for at this point
- timer C runs, briefly, and its relay activates the solenoid which drops the newly annealed case, then ends
- timer D runs, for however long you need before the cycle can be started again (load another case, let the ZVS/coil cool, whatever your needs are)
At this point the cycle will end or re-start, depending on the mode the timer is in (once then stop, or repeating).
I just went back and re-read this post...it meanders and repeats itself...and I'm too tired to go back and edit it again...sorry.
Edit: Okay, just went back and looked at the schematic again, and realized I didn't address the timer Start, Stop, and Gate switches (this confused me back when I first started). Firstly, there is no voltage associated with these switches, just momentary connections between the 0V (common) contact and the contacts for each command. What I mean is you just connect the 0V contact to one pole of a momentary switch and the Start contact to the other pole, and when you press the switch it connects the two and the timer receives the Start command.