Modem UPS @ Rs250/-

 Submitted below a very low-cost UPS for the modem. Modems / WiFi routers are usually powered by an adaptor and while the utility power fails then internet connectivity is disrupted even if the power is interrupted for less than a second. Providing a commercial 500VA  UPS only for the purpose is an expensive proposition. Small duration power interruption is well taken care of with zero change over time as it uses no relays. The majority of apartments start the backup generator automatically within minutes while the modem power is interrupted. Even with an inverter or mains ups feeding the modem fail to avoid a reset of the modem as those UPSs use relay change over (for off kine UPS) resulting in power interruption for few milliseconds that the modem is not able to tolerate. Video here https://youtu.be/kcugHjLLIPU Materials required :-…

Read More

Phase angle control using Arduino

Submitted below ac load management by delayed phase angle triggering to opto-coupler(U3)  interfaced triac (U4) for single phase load control using Arduino nano. Proteus file and the code for simulation are available at the bottom. For video watch at down below or use this link https://youtu.be/VpHoE_2MlEo Circuit Explanation It uses an Arduino nano which receives zero cross pulses (ZVS) at pin at Pin 2 and delayed output pulses are developed at pin 3. Control is done at A0 through a variable resistor (POT-RV1). A small step down transformer delivers 12 volt ac which is filtered by a bridge rectifier BR1 and then a blocking diode D1 and then filtered by capacitor C1 that feeds a 3 terminal regulator that gives 5 volt duly filtered again by C2 for powering the entire circuit. Function of D1 is very interesting. It separates…

Read More