I have an "Andersson Powerbank 20.000 PD/QC 3.0" like this:
shorturl.at/uzR46
This powerbannk turns off after 30 seconds if the output load is less than 80mA. I found this video on Youtube on the Mr. Carlsons Lab channel that points out exactly my problem:
I took an screenshot of his drawings and made my own circuit out of that in EasyEda, because i want to make an own PCB for that.
So i need to know if i have done it correctly. Here is my schematic. The timer i use is an 555 timer:
My goal is to make a PCB that i just attatch to the USB cable in some way. I do not want to open up the powerbank and fiddle with the internal circuit.
My second question is what will happend if i use an PD or Quick Charge cable that delivers up to 20V to an computer etc. Will my circuit be affected by that? if yes, how can i prevent it?
The cycle of the 555 timer is not affected by the power supply voltage, but the absolute maximum rating of the IC must be adhered to.
Many 555s don't accept 20V, so add 3.3V LDO to run at 3.3V at any time, or made with a high-voltage 555 timer like the BD9555FVM.
Assuming you are using an Arduino with your powerbank (this is after all an Arduino forum),
why don't you let the Arduino do this.
An Uno already uses about 50mA, so let a pin (or two pins) pulse that extra 30mA periodically.
There have been many examples on this forum over the years. Do a search.
One second 'on' seems long. could be that 100ms is already enough to trick the powerbank.
Leo..
I'm going to use the powerbank for my motorcycle rides where i constantly want to power an GoPro camera without the powerbank shutting down. I want GoPro to be at top charge at all time.
This is just a 5V unit, and the circuit will work fine, but i want to be on the safe side. if other should grab the cable and put it in a Macbook Pro i want it to work without letting any smoke out
Go to the website of e.g. RS Components, Mouser, Farnell etc.
Navigate through the product tree until you get to a category like "DC DC converters" or "Linear regulators"
Use the product filter settings to select only devices that have a maximum input voltage of greater than 20V (I would use a margin, so don't pick a part that accepts up to 20V, but go a bit higher than that)
Evaluate the matches you find for suitable part, primarily looking at output voltage (note difference between fixed and variable output voltage). Notice availability and price.
For the part(s) that appeal to you, decide how you will source them. You can order through the website you're on, or google for different sources.
Alternative approach, if you have a favorite (web)shop you're ordering from:
List their linear regulators
For each part that seems suitable, look up manufacturer's datasheet
