In the review, an updated version of the electronic load - the HD35 model from the company RD, with a built-in trigger for testing chargers with fast charge function
1. Appearance and equipment
The device comes in a plastic box, and this is very correct for both transportation and storage. Boxing made of soft plastic, which has a positive effect on durability
In addition to the load itself, there is nothing more
Externally, the device is practically no different from previous models of electronic loads of the LD series.
The power connectors are still the same USB-A, MicroUSB, Type-C:
Segment indicator of red light.Two SET and OK buttons to control the device. And another button is the inclusion of a trigger and switching the type of standard for fast charging. Three LEDs of different light to indicate the operation of fast charging modes:
The current is adjusted by a trimmer resistor Bochen 3296 10 kOhm
To cool the power elements there is a radiator with a fan. The fan turns on at a current of 2A or higher or when the radiator temperature reaches 40 degrees.
In circuitry, there are practically no differences from previous models.
TIP 122 bipolar transistor (100V, 5A) and LM317 current stabilizer:
Current Shunt 0.025 Ohm and Schottky Diode:
Microcontroller control N76E003AT20
Shift Register TM1650:
Trigger enable button:
- The “OK” button performs the function of turning the device on and off. Also, with a quick double press, it allows you to set the voltage in the fast charge testing mode from 5 to 20 V.
A long press of the button changes the starting mode of operation.
- The “SET” button switches the readings between current, voltage and power. To do this, press it once.
When high current protection (5V) is activated, OPP is displayed on the screen.
When overheating above 80 degrees, OTP is displayed,
If the voltage is higher than 25 V, OVP is displayed.
To activate the fast charge trigger mode, you need to hold the “Trigger” button, then the QC 2.0 mode will turn on and the red LED will light up.
When pressed again, there is a switch: on QC3.0 - green LED
FCP / AFC blue LED
And then all three LEDs light up - this is AUTO mode.
In QC2.0 mode, “-05.0” is initially displayed on the screen, which means that the load supply voltage is 5 V,
To switch the voltage, you need a quickdouble pressing the OK button, while the red LED starts flashing, then by pressing the OK and SET buttons, you can manually change the voltage according to the values of 5V, 9V, 12V and 20V (if it supports the charger).
In QC3.0 mode, -05.0 is also displayed on the screen, but the voltage can be changed already in 0.2V steps
FCP / AFC modes: AFC9 - mode for charging Samsung phones), similarly, you can switch to FCP9 mode (mode for charging Huawei phones)
In all modes, you can adjust the current strength, to see the value of the parameters on the indicator, you need to hold down the "trigger" button.
Also, do not forget that by connecting this pair to the computer via Bluetooth (UM25C allows you to do this), you can view the current and voltage graph in test mode.
In the idle mode (xx), the load consumes a current of 0.01 A. With the fan running, the current is 0.2 A.
This load should have been sold initially asthe only and functional option, because the cost of the device practically does not differ, but everything was done for the gradual introduction of standards for greater profit to the manufacturer. In any case, the load was successful. Of the minuses, all the same poorly readable indication of a red glow.