New Cheap Chinese Soldering Plates

[clearchris]

I was browsing on ali, and I'm seeing a bunch of these super cheap soldering hot plates. I was going to make one, but it's really hard to justify DIY when you can buy a plate for under $10.

Most look pretty functional, one looks like it needs to have the plate flipped, and they could all stand to be countersunk and swap the screws for flat head ones. Would be nearly trivial to install an arduino, thermocouple and ssd for fine control.

https://www.aliexpress.com/item/1005003127491986.html
https://www.aliexpress.com/item/1005001445767919.html
https://www.aliexpress.com/item/1005002383494461.html

[sam_sam_sam]

I like the first one and really like the last one for sure thank you for sharing the links

When you do get the micro controller program written can you please post the files because I would really like to get them working to be able to repair led strip and things like that

[megaraider]

Originally Posted by clearchris

Most look pretty functional

Aside from the plate size (75x75mm vs. 120x75mm) and price (1st vs. 2nd & 3th) I'm not sure if the heating element isn't the same... because they state the same constant power consumption at the same temperature setting.
Of course in either 3 options you'll get twice the time to get the settling 260ºC temperature, and possibly some temperature fluctuations because these were designed to operate on 240V, not 120V.

Overall, it doesn't really justify DIY... go for it.

[diif]

They aren't new, they've in the shopjimmy led rework station and are also used on their own for replacing LEDs.

[sam_sam_sam]

Yes they are not new item but the plate size is some what new because all ones that I have seen have been very small in size

But temperature control to me would be very important to be controlled for best results from a device like this although 500*F is not extremely high temperature for a heating plate for heating up solder on a circuit board if they used lead free solder you are going to play hell using this device for that type of solder


I am going to have to find another seller for this item because they do accept PayPal as payment and I will not use a credit card for this website because I have issues in the past with certain seller

But I going to buy the third one that was listed an do some experiments with it you might even need to use a a hot temperature controlled air gun for best results

[diif]

No, really, nothing new about the size either, mine is over two years old.

[redwire]

All of these heat plates are rated 220V. Looks like only one factory in china lol.
I don't know if the PTC works good enough for 110VAC operation? Don't get fooled by the 110V plug.

[sam_sam_sam]

I had bought some 24 volt ones and tried to run them on 12 and it did heat up but I did not have temperature sensor device to take it temperature

[redwire]

I've worked with LED's on aluminum MCORE pc boards, using hot air. It takes a lot of heat and too much will burn the LED melt the silicone lens.
Now I blast hot air on the backside to stop that from happening but still killed LED's from the heat. If they have a big thermal pad, even more heat is needed.

So I wanted to get one of these low cost hot plates, but almost all are 220V. Some offered with "US 110V plug" but say 220V in the ad.
I found part number YG400W-N is 220V, and YG-400W-W is 110V 400W in the 120x70mm size.

[clearchris]

Originally Posted by redwire

All of these heat plates are rated 220V. Looks like only one factory in china lol.
I don't know if the PTC works good enough for 110VAC operation? Don't get fooled by the 110V plug.

I think there might be 2 factories, I have seen two basic styles.

Because of how the PTC heaters operate, I'm not sure there's much of a difference in heating via 120 and 220v. It's not a normal resistive heater, the resistance varies as the temperature increases on a logarithmic scale. So, if the 120v power heats it a less quickly, the heater keeps the resistance low. Nearer the target temperature, the resistance rises quickly, to the point where I'm not sure if 100v difference really matters much. It might mean the top temperature is a few degrees less and it takes some seconds more to get to the top temperature.

I have seen documents that basically lump 120-380v in one basket, and others that say you need different heaters for 120 and 220v. It probably depends on the precision of the ending temperature required.

I haven't pencil whipped the numbers myself, for $10 I'll take a gamble and see if it works.

https://dbkusa.com/blogs/whatisptc/h...tc-heater-work

[megaraider]

Originally Posted by clearchris

Because of how the PTC heaters operate, I'm not sure there's much of a difference in heating via 120 and 220v.
https://dbkusa.com/blogs/whatisptc/h...tc-heater-work

That guy almost nailed it… aside from a mistakenly confusing Power (or Energy) with Voltage, what a great shame
U=RI
P=RI2 [Power (or Energy) = resistance x squared current]

Here the concern is the amount of Energy released as heat.
Thus, since they where designed to work on 240V you'll end up with a straight line (logarithmic and power of 2 cancelling each other).

Originally Posted by megaraider

Of course in either 3 options you'll get twice the time to get the settling 260ºC temperature, and possibly some temperature fluctuations because these were designed to operate on 240V, not 120V.

Overall, it doesn't really justify DIY... go for it.

[clearchris]

Originally Posted by megaraider

That guy almost nailed it… aside from a mistakenly confusing Power (or Energy) with Voltage, what a great shame
U=RI
P=RI2 [Power (or Energy) = resistance x squared current]

Here the concern is the amount of Energy released as heat.
Thus, since they where designed to work on 240V you'll end up with a straight line (logarithmic and power of 2 cancelling each other).

Isn't logarithmic x^10 and power of 2, well, x^2. Wouldn't we just see some flattening, and not a straight line?

[redwire]

For a constant resistance, 1/2 the voltage gives 1/4 the power.
But these things have a PTC non-linear resistance and hard to tell what power and temperature it will settle into steady state. I don't think you can run the 220V plate on 110V and expect 250°C because the power is much less. If the PTC is say 500ohms at 250°C, for ~100W at 220v, that would only be ~25W at 110V so the plate would go cooler.

Most Ali stores have the option for a 110V or 220V plate. I noticed they are rated 400W 220V and 300W 110V for the larger 120x70mm one. Other stores are silly with a 110V plug option but looks like the 220V plate is what gets shipped.

[clearchris]

Yeah, I bought one on amazon, the one with the silly plug. There's a review with a pic of an infrared thermometer saying it reaches 230C, which is actually fine for me. Adding a touch of hot air might actually be better, less chance of frying the leds from a plate that is too hot.

Technically, if I want to run a short 15' extension cord, I could have 220v at my bench. I may even have a 110/220v transformer kicking around that I could also use. But I admit, that would be less convenient.

https://www.amazon.com/gp/product/B08R7PKLDH/

I should have it thursday, I'll post a review.

[megaraider]

Originally Posted by clearchris

Isn't logarithmic x^10 and power of 2, well, x^2. Wouldn't we just see some flattening, and not a straight line?

Yes... straightened line (my mistype).

Originally Posted by redwire

For a constant resistance, 1/2 the voltage gives 1/4 the power.

YES, very well seen!! NO room to bend the laws!!

Originally Posted by clearchris

I may even have a 110/220v transformer kicking around that I could also use. But I admit, that would be less convenient.

It will become handy... imo.

[stj]

i have one of those plates for changing flashlight leds
they work but you need to be quick or they will cook your board and make it go yellow.
i may add a controller and thermocouple so it can ramp down or just not get so hot.

it's fine for changing one part or using solder paste but not for doing work that takes several minuits.

[clearchris]

Originally Posted by stj

i have one of those plates for changing flashlight leds
they work but you need to be quick or they will cook your board and make it go yellow.
i may add a controller and thermocouple so it can ramp down or just not get so hot.

it's fine for changing one part or using solder paste but not for doing work that takes several minuits.

I can believe it, 240-260C is the top end of the range. This is my next project after finishing the signal tracer, should be quick to knock out a design. I think the hardest part will be figuring out how to attach a thermocouple to the plate.

[stj]

thermal adhesive to the underside

[clearchris]

Originally Posted by stj

thermal adhesive to the underside

Thanks for the idea. Kapton tape should probably work in this instance, there's little risk of the tape falling off and burning up since it's already temperature limited.

[redwire]

People are using stoves, electric frying pans, steam irons, waffle irons etc. as hot plates.
These seem to be a PTC element wrapped in Kapton tape and then stuffed into the aluminum base.
One critical part is the cool down rate, once you get reflow and pull power it's probably too long to cool and wrecks semi's? Need around 4-6C/sec ramp down.

I'd add a bead thermocouple and maybe a cheap STC-1000 PID controller or just use a triac light dimmer if it's too much heat.
What I find with thermouples is they don't read accurately, they can read low if the mounting has high thermal resistance. Tape and glue have to be done well. A crimp lug bolted down is best but you don't want another screw sticking up. Maybe the underside at the legs would work.