Review on Comparator Measurement Protection Overvoltage Undervoltage by Alan Singh

Update 210709: Scroll down for clarified operating instructions This voltage indicating and limiting unit is a suitable device for setting not only the limit voltage but also the hysteresis of this voltage and it has timer functions, which are not documented here in the declaration. The 3.3 V CPU voltage is also provided by the 4266-2, which can handle input voltages of up to 41 V. I tested it at 31V, the limit of my desktop PSU, and it worked fine at 80mA, although the relay got a bit noisy when turned on. But I'm giving it a solid 3 for a number of reasons. 🔹️Firstly, this is a hobby block not intended for panel mounting. You can panel mount it if you unsolder the screw connectors and relays and fold them onto the back of the board, but that's a blueprint. I would consider it more valuable as a set if these three items were packaged separately. In this case, too, you have to glue extension cords to tiny buttons. 🔹️Second, the most dissipative element on the board is a resistor connected in series with the relay coil installed UNDER the display. If and when it burns out, then repairing it is very, very difficult. 🔹️ The ergonomics of the work are excellent, but you won't recognize that from the instructions. It's not just a Sino-English problem, it's clearly a logic problem with poorly designed programming and operational procedures. Earth, it's annoying to use this in an electric car with a traction battery floating around. Not surprising for a device in this price range, but it should be noted that many high-voltage DC systems are floating for safety reasons. I bought it to monitor and control the charging of an 80V traction battery, but at the moment this is being used to charge a 12V LiFePo4 battery from a 34V solar panel (see diagram). I'd rather use a dedicated charge controller for this, but for now it gets the job done._______________🔸️Features:1. User can set upper and lower voltage limits; V+ measurement input is DC 0-100V, measurement accuracy +/- 0.1V; 9-24V DC power input+2. The settings are saved and will not be lost when switched off.3. Newly added delays are 0-99.9 seconds for retraction and 0-99.9 seconds for release. 🔸️Functions: 01: Voltmeter relay does not trip, displays the measured voltage 02: Charge monitoring When the measured voltage is lower than the lower limit, the relay closes; when it is higher, it opens; 03: discharge monitor: when the reading exceeds the upper limit, the relay closes, when lower, it opens; 04: Interval: The relay closes only when the measurement is out of limits 05: Out of interval: The relay closes only when the measurement is out of limits Tip: The controller automatically determines which limits, V1 and V2 the upper limit voltage are, and which is the lower limit. User Manual 6 kinds of parameters that can be set, P0-P5.P-0 (function setting): Functions F-01 to F-05 are described above. P-1 (voltage setting V1): parameter value from 0.0 to 99.9V; P-2 (voltage setting V2): parameter value from 0.0 to 99.9V; P-3 (tension correction). ): The entire display flashes to show the currently measured voltage value. Press [+] or [-] to correct this voltage. P-4 (on-delay time T1): 0.1 to 99.9 seconds; the relay closes only if the pick-up condition is continuously fulfilled for the time T1; P-5 (off-delay time T2): 0.1 - 99.9 seconds; the relay opens only when the open state is detected for a continuous time T2; 🔸️ Working mode: When switched on, the measured voltage is displayed. 🔸️ Energy saving options [Short press on SET]: Cycle indicator turns on and off, but the program is still running [Long press on SWI]: The display flashes twice: If no button is pressed for 10 seconds, the display turns off, but the program continues. [Short press SET] resumes the display temporarily. [Long press SWI] The display flashes three times to confirm exiting sleep mode. Every time the display is off, the other 3 buttons are disabled. Setting mode [Press and hold SET] to enter the parameters (P0 to P5). stop all functions; the display shows "P-0", the currently selected parameter [short press SWI] changes between P-0 and P-5. [Short press SET]: shows the parameter value, the digit to be set flashes. [Short press press SWI] changes the position of the entered digit. [+] and [-] Change digit up and down [Short press SET] to return to parameter selection [Hold SET] Save parameter, exit setting mode and return to operating mode, start the selected function immediately.