DIY Induction Heater Builds and References

ElBarto

New Member
Thanks ill attempt it and see if I'm successful. I will be back here eventually :0
Btw If the dynavap completes the circuit would I get shocked? just curious
 
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ElBarto,

badbee

Well-Known Member
I am struggling to find the 12.6 usb c you are talking about. I only see 5 volts everywhere. Are you referring like a usb c wall plug or what. I am lost in that part. I'll just go to regular dc and deliver 12.6 directly to the BMS make it easier.
Are you looking for USB C input to 12.6 V for internal charging like this: https://www.amazon.com/Multi-Cell-Type-c-Step-up-Polymer-Charger/dp/B08KZGZJKX?th=1 I don't know anything about this product, just got curious...
 

ploooopp

Active Member
Would this work @TommyDee Aliexpress USB C BMS and sorry for the questions: which is ideal? running 2S of these 18650 2600mAh 25A discharge or 3S of these 18350 1200mAh 10A discharge what's the smallest formfactor button you can get? I've got access to a 3d printer, I want to integrate the batteryslots into the overall case kinda like a shelf with a sliding door for battery removal and charging, upon that shelf will go the ZVS unit, button and coil. Would it be dumb to forgo the BMS or any type of in case charging for removable batteries?
 
ploooopp,

TommyDee

Vaporitor
I'm sorry but that charger board at Aliexpress is for 1S only.
You can forgo the BMS but do put in a fuse in its place.
Smallest switch - hmm, got me. I like exposed contacts for a chamber switch.
 
TommyDee,

GI

Well-Known Member
I'm sorry but that charger board at Aliexpress is for 1S only.
You can forgo the BMS but do put in a fuse in its place.
Smallest switch - hmm, got me. I like exposed contacts for a chamber switch.
Sorry, but if one would use one battery 1S need only the fuse ? And where should be solded ?
 
GI,

TommyDee

Vaporitor
Two separate thoughts all together @GI - 1) The USB-C converter is only good for 1S configurations (4.2V) and 2) if you forgo the BMS, put in a fuse in its place. You will have no luck trying to run the ZVS with one cell without other things to bring the voltage up.
 
TommyDee,

roontoon

New Member
I'm building a half-pint and somewhere I thought I saw a post about modifying the induction coil itself. Is there an optimal size, number of coils, etc?
 
roontoon,

TommyDee

Vaporitor
Great question @roontoon - 33" of 12 awg wire; that is the original coil at 10 turns.

My perfect coil is 9 turns on the ID of 16mm and 3 turns on the outside for 3S and 12V operation.
The 9 turns is to make a 20mm long coil and the 'excess' is wounds around the outside.
I've done this with the stock coil wire and trimmed it a couple inches on each end.
 
TommyDee,
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roontoon

New Member
Sorry for the confusion. You are correct, those are 18 gauge magnet wires I had hooked up for a coil switch. I have since removed them.

What I did was to isolate the pads at the 3-pin connector. I moved the wires to the bottom;

20200922_175148.jpg

20200926_115833.jpg

Note that I moved the cut of the trace between the two horizontal wires.
Question here. I am currently building my first half-pint. Are these solid wires on the outside used to connect to the momentary switch? Also on the flip side are those cuts to isolate these pads for that purpose? And wires connected to the flip side to the trace and the wire loop connected to the power source? Wanted to be sure before I screwed anything up. Thanks.
 
roontoon,

TommyDee

Vaporitor
Your observation is correct @roontoon - I isolated pins 1 and 3 from the output connector to provide an alternate purpose, that being available pads for the low current switch for firing. I did one better though - I put springy contacts on the other side so the VapCap cap could be the shunt. This is the Fluxer Flite's CaS - cap as switch -. If this also makes it convenient to connect wires, by all means.

This was the final version of this effort. Top is the positive 12V to the momentary switch - middle is the center-tap of the choke - and the lower wire is the "gate enable" circuit. When shunting the upper and lower wires, the 12V power is reconnected to the gate-enable circuit. That is the whole purpose of the trace cut.

20200926_115745.jpg
 

GI

Well-Known Member
I really like a complete tutorial on halfpint and options, I'm too noob to follow all the posts ...ann, of course, didn't study electronic at all, maybe isn't for me.
 
GI,

TommyDee

Vaporitor
Page 13 has the best HalfPint tutorial you will find. The optional switch wires means to make the switch work is extra credit. I did this one for a very specific build.
 
TommyDee,
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GI

Well-Known Member
Two separate thoughts all together @GI - 1) The USB-C converter is only good for 1S configurations (4.2V) and 2) if you forgo the BMS, put in a fuse in its place. You will have no luck trying to run the ZVS with one cell without other things to bring the voltage up.
What i need to bring voltage up ? Something like this ? https://www.modmaker.com/naos-raptor-60w-10a

I would like to have one battery and swap it insted of charge on board.
 
GI,

badbee

Well-Known Member
What i need to bring voltage up ? Something like this ? https://www.modmaker.com/naos-raptor-60w-10a

I would like to have one battery and swap it insted of charge on board.
@GI , that's not what you need that is a buck circuit that lowers voltage, doesn't raise it. I looked around and boost boards that support a < 4.2 V input and > 60 W power are hard to find, you might need to build it yourself. I imagine this is why we don't see single cell IH's.

Edit: Spoke to soon, here is one that might work: https://www.amazon.com/DC-DC-Converter-Supply-Module-Wholesale/dp/B07NZ88CKC . It lists 4 V as the minimum but it might continue working down to 3.7 V ( Li Ion cell at low end). Current max is just barely high enough, might fail.

Edit 2: Here, this one is better, designed for Li Ion cells, still just barely high enough current out: https://www.amazon.com/JacobsParts-Step-up-Converter-Adjustable-Regulator/dp/B079YX761G

P.S. Can you tell I was bored this morning...
 
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TommyDee

Vaporitor
What i need to bring voltage up ? Something like this ? https://www.modmaker.com/naos-raptor-60w-10a

I would like to have one battery and swap it insted of charge on board.
@badbee 's got it right. A single cell IH would be simple to charge/change but the minimum input voltage for the IH is 5V, and at that, it doesn't put out much power. You do need a 100W or so boost converter to bring that power level up. You need about 50-70 watts of output. The IH would need to be tuned to a fixed voltage or you need to set a voltage to some level around 10V.

Math will help determine the performance required for the cell. Let's pick low voltage performance - 3V x 20A is 60 watts. Nominal voltage - 3.7V x 16.2A = 60 watts. Throw in an efficiency factor and you would need 25 amp continuous cell output capability.

Now feed that cell into a DC-DC boost converter. Again, 100W minimum should suffice and manage heat well enough. It would take your 3-4.2V input and regulate it to the output you need. There are tricks that can be played to tune an IH to a preferred input voltage level. Most of these converters have an input and output range. This makes tuning an IH to personal preference a lot simpler.

The linked converter in your post is a buck converter that changes 12V to 3.3V. 3.3V is a very specific requirement for certain types of computer chips. It has nothing to do with batteries. 3.3V is the 5V of yesterday in terms of integrated circuits.

@badbee -
  • Input: 3-35V DC 9A, Output: 3.5-35V DC 6A, Max Power: 100W when input and output both exceed 20V, otherwise 65W.
That 9A input will be exceeded by gobs. A 2S configuration might work up to 60 watts. Having a voltage adjust makes this a worthy option.
 

TommyDee

Vaporitor
I'd love to see a 1S solution work. That 15-20A draw has to be managed at the converter.

You can do 2S without an inverter. Try removing 3 loops and the associated wire from the coil. A 7 turn coil should make for a good starting point for a 2S heater. The coil will get a little warmer but it should cook at around 60+ watts. Haven't tried one yet but that is the right formula.
 

badbee

Well-Known Member
@GI , I wanted to see you experiment with the 1S just so I could see the result. Unfortunately failure and some waste of money was the most likely result... Does that make me a bad friend? Good luck with your project.
 
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