Question 1

How would i use this as a constant voltage supply if i don’t want a constant current supply (eg, i don’t want to accidentally spike the output v) ?

Accepted Answer

For me this has been a marvelously useful device.   I power it with the charger "brick" from a retired laptop PC, capable of as much as a couple amps at 25VDC.    The specifications don't make it clear, but you independently set the maximum output current and output voltage using the on-board 10-turn pots while monitoring it on the display.   For example when charging a lithium-ion battery, its specs might suggest a the maximum charging current of 0.5A and maximum output voltage of 4.2V.   So first, you set the open-circuit voltage to 4.2V.   Turn the output current to minimum and connect the batery.   Assuming the battery is pretty well discharged, when you first connect it you could potentially sink as much as several amps but that would hurt the battery.   No problem, you've set the current to minimum (a few mA).  When you connect the battery, turn up the current to 0.5A; the voltage will rise as you turn up the current, probably settling around 3.5V.   (I am assuming that your power source will easily supply the required power.)  As the battery charges, the voltage will gradually increase to 4.2V while the current stays at 0.5A.   But once the voltage gets close to 4.2V the current will start to taper off.   If left for several hours the voltage will still be at 4.2V but the current will be only a few mA.   So the supply acts like constant current, then transitions to constant voltage.    I hope this answers your question.   I  haven't seen any evidence of loss of control over either output voltage or current.   FYI it's worthwhile to experiment with the unit connected to an output load resistor first, to get an understanding of which buttons to press to read the desired values.   From memory, you can read input voltage and current, temperature of the heat sink in F or C, and output voltage and current.   And you can also read output voltage independent of supplying power to the load (i.e. it can act like a voltmeter).

Question 2

What does opp error mean?

Accepted Answer

Dear customer,
OPP:Over-power Protection
When output power reaches 35W, OPP will be enable.
Best regards.

Question 3

Is there an operating/owners manual

Accepted Answer

Good day.
You can get the user manual on product detailed page ---> Product information ---> Technical Specification ---> User Manual [pdf ]
You can also get it via the link below:
https://images-na.ssl-images-amazon.com/images/I/C1RCvx6bFMS.pdf
If there are any problems, please feel free to contact through Amazon's direct messaging service:
https://www.amazon.com/ss/help/contact/?_encoding=UTF8&marketplaceID=ATVPDKIKX0DER&ref_=v_sp_contact_seller&sellerID=AFHAE9RJVUMB
Best regards.

Question 4

I need to increase voltage from 11V to 15V, can it do it?

Accepted Answer

Yes this will work.  This morning I needed to run 2 12V PC fans from a USB 2.0 port.  It worked drawing around 400mA.

Asin	B078Q1624B
Best Sellers Rank	#69,678 in Computers (See Top 100 in Computers) #484 in Computer Power Supplies
Brand	DROK
Color	blue-1
Customer Reviews	4.3 4.3 out of 5 stars (1,006) 4.3 out of 5 stars
Input Voltage	32 Volts
Item Dimensions	5.2 x 8.2 x 3.2 centimeters
Item Weight	90 Grams
Manufacturer	DROK
Mfr Part Number	REES-1822
Model Number	REES-1822
Number Of Items	1
Number Of Outlets	1
Output Voltage	32 Volts
Plug Type	Type A, Type B
Power Source	DC
Upc	678535742056

DROK DC Buck Converter, 5.3V-32V to 1.2V-32V 12A Adjustable Power Supply, 5v 9v 12v 24V 30V 32V Step Down Voltage Regulator with LCD Display Volt Transformer Reducer CC CV for RV Solar Panel Golf Cart

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