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Tag: cheap

Modem UPS @ Rs250/-

ucpatnaik

 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 :-…

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PWM Module having Adjustable Frequency & Duty Cycle with LCD Display

ucpatnaik

A very low cost module (< $3) with excellent Features: LCD display of frequency and duty cycle  PWM output can be set to the specified frequency and duty cycle. Wide frequency range with high accuracy; Serial communication features, TTL level Parameter settings The module has four independent buttons, used to set the frequency and duty cycle, momentary press (increase or decrease by a unit) and long press (fast increase or decrease). Parameters get automatically saved, even after switching off and then switching on. PWM output, one can set frequency & duty cycle; It has 4 Frequency ranges, automatic switching: 1   xxx (no decimal point): the smallest  is 1Hz, range  1Hz to 999Hz; 2   x.xx (decimal point at hundred) the smallest is 0.01Khz, trange of 1.00Khz to 9.99Khz; 3   xx.x (decimal at in ten): the smallest unit is 0.1Khz; value range…

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