3 ms·

USB type-c power delivery is 5 or 20V it’s not a variable voltage supply. Switching between the modes isn’t fast enough and if you do try to pulse modulate it

USB type-c power delivery is 5 or 20V it’s not a variable voltage supply. Switching between the modes isn’t fast enough and if you do try to pulse modulate it you more likely than not to kill your power supply as they weren’t designed for that.

rektide 6y ago
there is a Programmable Power Supply Mode (PPS) that was added[1] that lets a device dial in exactly what voltage it wants, as the parent comment said, no buck needed (assuming it's within current limit). it made sense to specify. variable output doesn't add much complexity, and it can reduce part count in the exact way we see herr- remove a voltage converter. on the other hand, just a guess, but I'd guess well under half of supplies (wall & battery) have PPS support. just last month I went out & bought the pro version of the battery back I had been using: same size, same capacity, more expensive but it had PPS, which I wanted to play with (as a hobbyist), and can supply more watts (honestly not that important to me atm). [1] https://www.pengohome.com/Learn_Detail.asp?LiD=D15D68D2FEB0FC44E732AA2EF5A01CFE https://www.pengohome.com/Learn_Detail.asp?LiD=D15D68D2FEB0F...
- dogma1138 6y ago
  >The PPS standard refers to the power supply can exchange data with the power supply every ten seconds, so that the power supply can dynamically adjust the output voltage and current according to the condition of the receiving product specifications. This isn't suitable for this. In general you do not do any high frequency modulation in the power supply, this is not the component for that. You put your capacitors and the switching required where it's needed more or less the supply can be constant.
  - rektide 6y ago
    We can start the discussion on soldering irons, I guess. There seem to be two main strategies. I'm not super well versed on the pro's & cons of each. A lot of soldering irons use a resistive heating element. Dump current in, get heat. Higher end soldering irons tend to use high frequency inductive heating. Hakko has a write up here[1]. Agreed that for a switching supply, PPS isn't going to help a lot. For a resistive soldering iron, a PPS capable USB power source would be very helpful. All that's needed is a control loop, to monitor temperature & adjust the asked for input voltage and/or current. Honestly not sure what the Pinecil or the well known TS100 soldering iron are, resistive or RF inductive. It'd be great if they were RF inductive heating, & PPS wasn't helpful, as the much finer control would be great. I hadn't considered that they could be. [1] https://www.hakko.com/english/products/hakko_fx100.html https://www.hakko.com/english/products/hakko_fx100.html
deleted 6y ago
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rektide 6y ago

there is a Programmable Power Supply Mode (PPS) that was added[1] that lets a device dial in exactly what voltage it wants, as the parent comment said, no buck needed (assuming it's within current limit). it made sense to specify. variable output doesn't add much complexity, and it can reduce part count in the exact way we see herr- remove a voltage converter. on the other hand, just a guess, but I'd guess well under half of supplies (wall & battery) have PPS support. just last month I went out & bought the pro version of the battery back I had been using: same size, same capacity, more expensive but it had PPS, which I wanted to play with (as a hobbyist), and can supply more watts (honestly not that important to me atm). [1] https://www.pengohome.com/Learn_Detail.asp?LiD=D15D68D2FEB0FC44E732AA2EF5A01CFE https://www.pengohome.com/Learn_Detail.asp?LiD=D15D68D2FEB0F...

dogma1138 6y ago
>The PPS standard refers to the power supply can exchange data with the power supply every ten seconds, so that the power supply can dynamically adjust the output voltage and current according to the condition of the receiving product specifications. This isn't suitable for this. In general you do not do any high frequency modulation in the power supply, this is not the component for that. You put your capacitors and the switching required where it's needed more or less the supply can be constant.
- rektide 6y ago
  We can start the discussion on soldering irons, I guess. There seem to be two main strategies. I'm not super well versed on the pro's & cons of each. A lot of soldering irons use a resistive heating element. Dump current in, get heat. Higher end soldering irons tend to use high frequency inductive heating. Hakko has a write up here[1]. Agreed that for a switching supply, PPS isn't going to help a lot. For a resistive soldering iron, a PPS capable USB power source would be very helpful. All that's needed is a control loop, to monitor temperature & adjust the asked for input voltage and/or current. Honestly not sure what the Pinecil or the well known TS100 soldering iron are, resistive or RF inductive. It'd be great if they were RF inductive heating, & PPS wasn't helpful, as the much finer control would be great. I hadn't considered that they could be. [1] https://www.hakko.com/english/products/hakko_fx100.html https://www.hakko.com/english/products/hakko_fx100.html

deleted 6y ago

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