Induction brass annealer redux

[GrocMax]

That would be Ma'am.

VA meter doesn't carry any appreciable current on those wires, it measures voltage drop across the shunt (XX millivolts drop = YY amps) to determine current, the cut you see in the shunt bar is done precisely so that shunt has for instance 50 mV drop at 50 amps, and is linear from 0.

The fuse for the AC end of the PS isn't the same as the current output capability of the DC end of the PS.

The size of the wire relates to the maximum current seen, also to reduce voltage drop (and heat). You could probably get away with 18g or smaller high quality wire at intermittent duties, but you'll heat the wire pulling that much current.

 

[Gina1]

The 14 gauge wire carries the high current from the 48 volt PS to the contactor relay, through the V/A shunt, than to the the inductor PCB. That being said, what fuse are you talking about? The smaller wires for the V/A are "sense" wires and do not have to be large wires. No such thing as a dumb question. Always glad to help.

Gina.. Not Sir... Ma'am

 

[8mm]

The 14 gauge wire carries the high current from the 48 volt PS to the contactor relay, through the V/A shunt, than to the the inductor PCB. That being said, what fuse are you talking about? The smaller wires for the V/A are "sense" wires and do not have to be large wires. No such thing as a dumb question. Always glad to help.

Gina.. Not Sir... Ma'am

I am sorry about that. (head bowed)

The fuse is the 10A inlet one. I'm used to fusible links that look heavier.
Thank you for the info, Ma'am.
My build is going well, if slow. All the parts are here,but filling the case too quickly. I wound the coil and it sprung to 1-5/32" which will be better (?) for my .323 brass.

 

[Gina1]

I am sorry about that. (head bowed)

The fuse is the 10A inlet one. I'm used to fusible links that look heavier.
Thank you for the info, Ma'am.
My build is going well, if slow. All the parts are here,but filling the case too quickly. I wound the coil and it sprung to 1-5/32" which will be better (?) for my .323 brass.

1-5/32" should not be a problem. The original 1-1/8" coil was set up by hollywood for .308 cases. The closer the case is to the coil, more current will transfer to the case, the faster the case will heat up. (the basic GinaErick design)

Good luck on your build.

Gina

 

[SGK]

Some pretty cool stuff here. I'm thinking about a build.

I'd like the current limiting and so that puts me in the more expensive 48V PSU pot.

I'm happy to manually add the cases but it would be quite cool if it could automatically detect a case in the coil and start accordingly after a short delay. Might need some help exploring how to do this and whether it is worthwhile. I've done a bunch of audio electronics (circuit design, pcb design, SMD soldering etc) but nothing like this before. (With all my audio stuff I specified the enclosure panel drilling but outsourced the fabrication to Modu. Doing so here would not make economic sense. So some of the enclosure and mechanical fabrication may proof more challenging.

I see some of the parts are now more expensive and some may need to change. (BTW, Gina if the first post can be edited an index with links to key posts would be cool. It has taken a couple of hours just to read through the 46 pages!)

I'd prefer to minimise the mains voltage stuff and so run fans, pumps and relay off 12V. I was thinking it would be easy to peel 12VDC from the 48V PSU but the 12V PSU is so cheap it's not worth the hassle. I see the Sestos timers on Amazon are 12-24VDC supply now.

Dumb question for now. What is required for the part "shunt"?

BTW some rather large fuses used in the schematics here. 10A x 120V = 1200W. Could well protect much lower no? And even more so for the 3A timer fuses.


PS: Gina, I just watched your video again. Am I right that you have a certain amount of time to get the new case in (assuming you haven't hit stop) and it starts automatically once this time is up? Anyone zapped their fingers?

 

[SGK]

Probably won't find it since I made it, haha.

Really nice build. What are the dimensions of your enclosure? (Trying to get a sense of how compact a tidy build can be.)

 

[Gina1]

Wow, you did cover some material.

Yes I like the "constant current" unit from GrocMax it's a really neat design. And yes it uses a more expensive power supply. Again, it's up to you, what you want. Same for the design of you enclosure.
Take a hint from the pictures other builders have posted.
Granted 46 pages of posts is a bunch to go through.. Sorry I'm not an editor, So I will not be doing an index.

As far as the fans, other builders have used 12 VDC fans. No problems, I just used 110VAC fans, because at the time I had them. The Sestos Quadratic time is still available to run at 110VAC
Some where in the 46 pages, one builder included a start circuit, for when the case is inserted into the coil. (more reading on your part.)( I think it uses an optical sensor)

The "shunt" comes withe V/A meter.
A 10 amp main fuse was used for total protection. If the 48 V PS goes ..it blows. 10 amps is not that high a current. Same for 3 amps for every thing else.

Last question... The unit is running in "auto-cycle" with a 3 second delay for the next case. I did ZAP my fingers once. I was curious (when I built my first unit) how much current I would draw if I inserted a small steel screw driver into the coil. It went from cold to red hot on less than 100ms. Burnt my fingers. Won't do that again.

Gina

 

[Gina1]

Really nice build. What are the dimensions of your enclosure? (Trying to get a sense of how compact a tidy build can be.)

Again, it's your design. The 48 volt PS takes up the most room. Some builders mount it side ways (front to back) So the unit is longer that way , but narrow on the bench. Some builders have mounted the PS under the main chassis board. All you have to do is think about what you want and how to do it.
If you go the "basic" GinaErick design, max current on the V/A meter is 12-12.5 amps.

 

[SGK]

The Sestos Quadratic time is still available to run at 110VAC

ok. The ones I saw on Amazon are 12-24V but I don't think that will be a problem. (It requires 50mA max.)

Some where in the 46 pages, one builder included a start circuit, for when the case is inserted into the coil. (more reading on your part.)( I think it uses an optical sensor)

I now understand better the use of OPB100Z by FishnDog et al. I suspect the OPB819Z may be a more useful form factor for me. I just need to figure out if I can get it to drive the start / stop of the timer directly.

The "shunt" comes withe V/A meter.

Thanks for this and everything else. I'm sure I will have other questions!

 

[SGK]

Again, it's your design. The 48 volt PS takes up the most room. Some builders mount it side ways (front to back) So the unit is longer that way , but narrow on the bench. Some builders have mounted the PS under the main chassis board. All you have to do is think about what you want and how to do it.
If you go the "basic" GinaErick design, max current on the V/A meter is 12-12.5 amps.

Thanks. It would be good to hear from dabeechman. I know there are an infinite number of ways to lay things out but I thought that was a nice compact design and shows what is possible. I'd love to get a better look at how he did his trapdoor as well as it is not apparent from the photos.

 

[SGK]

max current on the V/A meter is 12-12.5 amps.

Which is 5A with 120V primary. Add an amp on the primary side for everything else and I would have thought you'd have plenty. I would have thought a 6.3A slow blow more appropriate. But, hey, maybe I'm missing something and in any event anyone can build what they like.

Going back over GrocMax's current limiter stuff again now and then I'll focus on the IR control of stop/start.

 

[McHaggis]

As for size I stuffed it all in an old Compaq ATX case and I use the PC power supply for both 5 & 12 vdc needs. I’m also running the 750w 48 meanwell power supply.

 

[SGK]

Cool!

While I wait for parts to come from Asia, please can someone answer these questions:

1. what is the voltage potential at the Sestos B3S timer coins 2 and 12 (when not grounded)?
2. what happens if one presses and holds the "start" button? Does the timer wait for the closure of pin 2 to pin 1 top reopen before starting or will it operate with pin 2/start constantly grounded? (Same question with "stop" - does it wait for the grounding of pin 12 to reopen before stopping?)

 

[Gina1]

Cool!

While I wait for parts to come from Asia, please can someone answer these questions:

1. what is the voltage potential at the Sestos B3S timer coins 2 and 12 (when not grounded)?
2. what happens if one presses and holds the "start" button? Does the timer wait for the closure of pin 2 to pin 1 top reopen before starting or will it operate with pin 2/start constantly grounded? (Same question with "stop" - does it wait for the grounding of pin 12 to reopen before stopping?)

SGK... Hi

I never measured for a voltage differential between pins 1, 2, and 12. So I do not know.

As for question 2, I never had to hold the start switch down past the start cycle. (it is a momentary contact switch). But for you, I checked it out. The timer cycle starts when contact is made between pins 1 and 2. (as my unit is programmed for "auto-cycle") holding the start push button down, the unit just keeps going through the annealing cycle. (even after I let up on the button).
Pushing the stop button, stops the cycle. Continuing to hold the stop button, it remains stopped.

Gina

 

[SGK]

Hi. Thanks for that. That could make automating the start/stop easier. Then again, I'm pretty sure I can program a PIC to do the job. The code is only a couple of lines. The voltage is relevant to this as if above 5V a couple more components are necessary (but even then it's not complicated). If anyone gets a chance to check I'd appreciate it as I can continue to tinker while I wait for mine to turn up. (Obviously with a little more coding the PIC could replace the Sestos timer completely but as a display/input panel and relays are still required it's not really worth it.)

 

[dabeechman]

Thanks. It would be good to hear from dabeechman. I know there are an infinite number of ways to lay things out but I thought that was a nice compact design and shows what is possible. I'd love to get a better look at how he did his trapdoor as well as it is not apparent from the photos.

I am a bit biased, but I like my design due to how compact and neat it all turned out. I'll measure the dimensions tomorrow when I am back out in the shop. If I were to do it all over again, I would add another inch or so to the dimensions. It was a bit of work getting everything to fit and look right.

 

[SGK]

Thanks. I think it is a really elegant build. Neat, compact and tidy. Also, I couldn't see how you managed the trap door...

 

[dabeechman]

Thanks. I think it is a really elegant build. Neat, compact and tidy. Also, I couldn't see how you managed the trap door...

The trap door is integrated into the platform. There is a solenoid under there that controls an arm.

 

[SGK]

Question regarding the relay supply power (48VDC) to the inductor PCB. A lot of the earlier discussion on this point seemed to focus on a SPST relay. I'm planning to use a 12VDC coil, DPST-NO relay such as this one. I would like to clarify the necessary protective measures. I would have thought the induction PCB board would take care of the collapsing field from the heating coil when power is cut. That leaves just the 12V coil in the relay itself. I'm planning to merely place a 1N400X series diode (need to check what I have) across the relay coil (anode at GND and cathode at 12V). Am I correct?

@dabeechman your platform looks so compact. From the pics you posted I couldn't see how you'd tucked the solenoid so neatly under it. Pic?

 

[Gina1]

The trap door is integrated into the platform. There is a solenoid under there that controls an arm.

I think he was asking how your bell crank was configured and what solenoid did you use to drive it for the trap door.