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Topic: Really universal soldering controller (Read 773920 times) previous topic - next topic

Re: Really universal soldering controller

Reply #3405
Why not this way?
Single IC, no transistors, Schmitt trigger inputs, low pass filter (don't look at filter components - this is just a draft)

Re: Really universal soldering controller

Reply #3406
And this way you even have control of how fast it turns on separately from how fast it turns off:

Re: Really universal soldering controller

Reply #3407
Why not this way?
Single IC, no transistors, Schmitt trigger inputs, low pass filter (don't look at filter components - this is just a draft)
There is a lot of variants, but here I cannot see how you can reject 50Hz
Here is the sch.
http://dangerousprototypes.com/forum/index.php?topic=7218.3360


Re: Really universal soldering controller

Reply #3409
Make C1 and C2 large enough and you reject it.
Large enough, but what about the delay - that is unipolar cirquit and any cap, in low frequenses connected as low pass filter, acts as accumulator.

Re: Really universal soldering controller

Reply #3410
Here's another variant. Starts swinging the output at 5Hz. 10Hz is hardly rejected, and 50Hz doesn't have a chance. No delay on putting something to holder, 0.1s delay on getting out of holder.

I would make get-out delay even half a second (larger R4). Then even 1Hz noise does not have a chance.

Re: Really universal soldering controller

Reply #3411
Here's another variant. Starts swinging the output at 5Hz. 10Hz is hardly rejected, and 50Hz doesn't have a chance. No delay on putting something to holder, 0.1s delay on getting out of holder.

I would make get-out delay even half a second (larger R4). Then even 1Hz noise does not have a chance.
if your input is V2 let say for touch sensing board, what about input resistance and 2kv protection

Re: Really universal soldering controller

Reply #3412
if your input is V2 let say for touch sensing board, what about input resistance and 2kv protection

You can always put a TVS instead of D2 or even parallel to it, although the NAND must already have such in it. The input resistance at first NAND is the same as on other variants with 4001.

Re: Really universal soldering controller

Reply #3413
You can always put a TVS instead of D2 or even parallel to it, although the NAND must already have such in it. The input resistance at first NAND is the same as on other variants with 4001.
I already made working sch. it is here - attached and TESTED, saved x2 nands from one IC for other tasks
If you want to help us Pease make an extra input for "Hybernation" signal - to stop the heater the time we make a hot swap.

Re: Really universal soldering controller

Reply #3414
I already made working sch. it is here - attached and TESTED, saved x2 nands from one IC for other tasks
If you want to help us Pease make an extra input for "Hybernation" signal - to stop the heater the time we make a hot swap.

I don't get what exactly is unclear, but here it is - 2 gates, 4 diodes, 6 resistors, 2 capacitors. No need for transistors. And the inputs are exactly the same as on your circuit.

I just don't see the need for 4 transistors on your schematic when there are 2 free gates that do the same. I also don't quite understand what is the purpose of separate outputs for sleep and hibernation, given the fact that the controller only has one input for this.

 

Re: Really universal soldering controller

Reply #3415
sparkybg the circuit you have come up with is nearly the same as what I am using  :D

I am using a single sot23 transistor instead of second NOR only because I use protoboard instead of ordering pcb, lead pitch does not align with pads to separate inputs nicely. Otherwise single IC is much more elegant

Schmitt  trigger inputs are essential IMO, so 4001 is no good


Re: Really universal soldering controller

Reply #3417
I don't get what exactly is unclear, but here it is - 2 gates, 4 diodes, 6 resistors, 2 capacitors. No need for transistors. And the inputs are exactly the same as on your circuit.

I just don't see the need for 4 transistors on your schematic when there are 2 free gates that do the same. I also don't quite understand what is the purpose of separate outputs for sleep and hibernation, given the fact that the controller only has one input for this.
You did not get the meaning from the begining. The two inputs are connected together only because you did not accept the idea to asign exta input for "Hybernation " signal. It is thrue that is a luck of hardware for that, but it is possible to be done in a simple way. If you think your sch. is better, just do it, we will have other option fot thouch sensing board. My sch. is here.
Do you think the two diodies difers much more from the two fets ( as a parts )? As I can see the discharging of  C in your sch. is not ok, it still integrate, may be you confused the direction of diodes? Anyway , when you finish it, just tell us.

Re: Really universal soldering controller

Reply #3418
It would be great to connect the circuit on the back board by replacing D1-D4, TVS1, on DO-214AB (SMC).

These are on the edge already. And SMC has thermal resistance of 55C/W, DO-201 has 25C/W. I was even thinking of TO220 diodes there.

On this photo they are already at around 70-80C. SMC would go to 130-150, which is definitely NOT acceptable. Only the TVS can be replaced with SMC.



Re: Really universal soldering controller

Reply #3419
Do you think the two diodies difers much more from the two fets ( as a parts )?
No, but you have gates on the chip that do nothing, and there's 2 more parts in the sensor's BOM (3 if we count the larger capacitors also). Yes, it is not a big deal, bit it is there.

As I can see the discharging of  C in your sch. is not ok, it still integrate,
Your integrates too - 4.7k on BJT's base is equivalent of around R5 being around 470ohm on my schematic. And you can replace R5 with even 200ohm - 74LVC123 can handle this, but it is irrelevant - there's 1.8k and 100nF filter on the front board for SLEEP signal. And the delay that even 1K generates is way smaller than 1/100 seconds, which is irrelevant as well.

may be you confused the direction of diodes? Anyway , when you finish it, just tell us.
Then you can either swap the resistors or rotate the diodes by 180 degrees.

I don't have the parts in the drawer, so I wont make this any time soon. I may make it with TL072 opamps instead of gates - I do have these in the drawer.