Out of curiosity, i plugged my Pinecil into my Anker model A2322 60w USB-C PD brick with a 2M USB-C charging cable that was sure advertised as being capable of 60W PD, and says so on it, whatever that is worth. I bought these for my Pinebook Pro originally. Plugged the brick into my kill-a-watt power meter.
The display shows 15v on it, and the KAW shows it drawing 28W. Just to see if it was holding back unless/until it needed the juice i put the tip inside a spare "V6" style 3d printer printhead heatsink and held it in front of a fan. It struggled and continued to just get 15v.
Is this a bad cable maybe, or perhaps this is a firmware issue? This pinecil is from the 2nd production run, just received today.
01-23-2021, 03:47 AM
(This post was last modified: 01-23-2021, 03:48 AM by Ralim.
Edit Reason: Add note on usb-c only being 20V
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(01-22-2021, 07:29 PM)Timpanogos Slim Wrote: Out of curiosity, i plugged my Pinecil into my Anker model A2322 60w USB-C PD brick with a 2M USB-C charging cable that was sure advertised as being capable of 60W PD, and says so on it, whatever that is worth. I bought these for my Pinebook Pro originally. Plugged the brick into my kill-a-watt power meter.
The display shows 15v on it, and the KAW shows it drawing 28W. Just to see if it was holding back unless/until it needed the juice i put the tip inside a spare "V6" style 3d printer printhead heatsink and held it in front of a fan. It struggled and continued to just get 15v.
Is this a bad cable maybe, or perhaps this is a firmware issue? This pinecil is from the 2nd production run, just received today.
Hello,
This is expected behaviour. If you look at the details on that power brick it is only 45W on the usb-c port. ("60W" = 45W type-C +15W type-A).
As the soldering iron is basically a resistor its current draw is proportional to voltage.
As such it will not select the 20V range if the adapter cannot provide sufficient power (60W) for that voltage range.
And it will instead pick the highest voltage it can, without overloading the power adapter.
As most usb type-C adapters will shutdown very rapidly on overcurrent (or some just up and break), it instead takes the safest option of only using what the adapter advertises as in spec.
Also tiny note; usb-pd only goes up to 20V. 
(01-23-2021, 03:47 AM)Ralim Wrote: (01-22-2021, 07:29 PM)Timpanogos Slim Wrote: Out of curiosity, i plugged my Pinecil into my Anker model A2322 60w USB-C PD brick with a 2M USB-C charging cable that was sure advertised as being capable of 60W PD, and says so on it, whatever that is worth. I bought these for my Pinebook Pro originally. Plugged the brick into my kill-a-watt power meter.
The display shows 15v on it, and the KAW shows it drawing 28W. Just to see if it was holding back unless/until it needed the juice i put the tip inside a spare "V6" style 3d printer printhead heatsink and held it in front of a fan. It struggled and continued to just get 15v.
Is this a bad cable maybe, or perhaps this is a firmware issue? This pinecil is from the 2nd production run, just received today.
Hello,
This is expected behaviour. If you look at the details on that power brick it is only 45W on the usb-c port. ("60W" = 45W type-C +15W type-A).
As the soldering iron is basically a resistor its current draw is proportional to voltage.
As such it will not select the 20V range if the adapter cannot provide sufficient power (60W) for that voltage range.
And it will instead pick the highest voltage it can, without overloading the power adapter.
As most usb type-C adapters will shutdown very rapidly on overcurrent (or some just up and break), it instead takes the safest option of only using what the adapter advertises as in spec.
Also tiny note; usb-pd only goes up to 20V.
I'll grant you that a careful reading of the label does indicate that it maxes out at 45w either via 15v or 20v.
But it only drew 28 watts at 15v, and never switched up to 20v.
(01-23-2021, 04:16 PM)Timpanogos Slim Wrote: (01-23-2021, 03:47 AM)Ralim Wrote: (01-22-2021, 07:29 PM)Timpanogos Slim Wrote: Out of curiosity, i plugged my Pinecil into my Anker model A2322 60w USB-C PD brick with a 2M USB-C charging cable that was sure advertised as being capable of 60W PD, and says so on it, whatever that is worth. I bought these for my Pinebook Pro originally. Plugged the brick into my kill-a-watt power meter.
The display shows 15v on it, and the KAW shows it drawing 28W. Just to see if it was holding back unless/until it needed the juice i put the tip inside a spare "V6" style 3d printer printhead heatsink and held it in front of a fan. It struggled and continued to just get 15v.
Is this a bad cable maybe, or perhaps this is a firmware issue? This pinecil is from the 2nd production run, just received today.
Hello,
This is expected behaviour. If you look at the details on that power brick it is only 45W on the usb-c port. ("60W" = 45W type-C +15W type-A).
As the soldering iron is basically a resistor its current draw is proportional to voltage.
As such it will not select the 20V range if the adapter cannot provide sufficient power (60W) for that voltage range.
And it will instead pick the highest voltage it can, without overloading the power adapter.
As most usb type-C adapters will shutdown very rapidly on overcurrent (or some just up and break), it instead takes the safest option of only using what the adapter advertises as in spec.
Also tiny note; usb-pd only goes up to 20V.
I'll grant you that a careful reading of the label does indicate that it maxes out at 45w either via 15v or 20v.
But it only drew 28 watts at 15v, and never switched up to 20v.
That is entirely correct.
15V/8.5 ohms = 1.7A
1.7A * 15V = ~27W.
The iron does not contain a DC/DC converter so it cannot operate at 20V as it will over-current the supply and the supply will turn off.
(01-28-2021, 04:17 AM)Ralim Wrote: That is entirely correct.
15V/8.5 ohms = 1.7A
1.7A * 15V = ~27W.
The iron does not contain a DC/DC converter so it cannot operate at 20V as it will over-current the supply and the supply will turn off.
Hey Ralim, awesome firmware by the way, thanks!
Just to "show the work" on this all, you're saying the USB-PD 45W supply would be capable of 20V @ 2.25A:
45W / 20V = 2.25A
The iron is a 8.5 ohm load so at 20V would be 2.35A, thus causing over current on the 45W supply:
20V / 8.5 ohms = 2.35A
2.35A * 20V = 47W
Also, on a DC5525 @ 21V the iron tops out at almost 52W (not exactly 60W like on the printing):
21V / 8.5 ohms = 2.47A
2.47A * 21V = 51.8W
Is that more or less the calculation you're talking about here?
Hi,
The forum doesnt seem to notify me so apologies for the delay.
But yes thats the basic maths of it all.
Tips do vary in terms of resistance as they heat up as well as unit to unit.
The range of 7.5-8.5 is about the widest spread ive seen ignoring outliers.
The ~60W rating was mostly from 24V operation which you can theortically run at, but its on the absolute limit for the PD chip so its not advised.
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