So to power something off a USB port it has to be under 5 volts as thats how much a USB port gives out so you can check this by ; Looking at what battery is being used. 4 x aaa = OK. 4 x aa = OK. USB runs at 5v. The max current you can draw is 500ma. Therefore the max load is 5v x 0.5A=2.5. Watts.
Thanks for answering. @KyokoSasagava As long as the voltage is not more than 10% off and the power-supply can supply the same amount (or more) of current (Amps) this is in general fine. Do take care of the polarity of the plug. The + and - HAVE TO BE on the same side of the plug as on the original power-supply.
So for example getting 5V from a 12V source using 10 diodes in series would be bad, and the voltage could range from as much as 7V to as little as 2V, depending on the current draw. The 7805 has a minimum voltage of 7V to output 5V at 1 amp, so as long as you can guarantee this 7V you should be okay. Note that the output of the 7805 will vary
In every technical document, summary, and description of the ESP8266, the ESP8266 is said to be a 3.3V part. While weāre well into the age of 3.3V logic, there are still an incredible number of
\$\begingroup\$ Alright then slightly dumber question, the pressure sensor I have takes 5v of power, while outputting a voltage between 0.5v and 4.5v. Am I correct that I am still only dividing down from 4.5v to 3.3v since even though the pressure sensor takes 5v of power, the signal it outputs will only ever be between 0.5v and 4.5v. \$\endgroup\$
Most protection circuits cut off if voltage greater than 4.3 V or temperature greater than 90 Ā°C is reached. Below 2.50 V/cell the battery protection circuit may render the battery unchargeable with regular charging equipment. Most battery circuits stop at 2.7ā3.0 V/cell. So to achieve a full state of charge you'd normally want to aim at 4.2V.
Step 1: BOM (bill of Materials) For this Instructable you will need: 1 - LM7805 voltage regulator. 1 - Capacitor with the value of 0.33uF. 1 - Capacitor with the value of 0.1uF. 1 - 9 volt battery. 1 - 2.2 volt Red LED (you can use a different colored LED if you'd like, but then your final results may differ from what is displayed in the photos
It is not recommended to use 5 volts instead of the recommended 4. 5 volts, as the components in your device may not be designed to handle this amount of voltage. Depending on the device and the components inside, using a higher voltage than what is specified may damage or even destroy your device. Doing this may also void any existing
Voltage drop across a LED depends on a it's color, for blue led for example - 3.4V. So if you have 5V power supply, and want 5mA current through led (5mA usually gives good visibility), you need (5V-3.4V)/0.005A = 320 Ohm resistor. (I.e. this resistance will give voltage drop across resistor of 1.6V, remaining 3.4V drops on LED => 5V total)
Can I use a 9v adapter for 7.5 V? The long term effect of using 9 V instead of 7.5 V is unpredictable. It depends on the construction of the baby monitorās electronics. It may work or failā¦ Chances are that the 9 V adapter outputs a bit less than 9 V. What happens if you use 9V instead of 5V?
Two 1.5 V 1 A batteries connected in series (end to end) make a overall 3.0 V 1 A battery. If the batteries were connected in parallel (both + ends together and both - ends together), then you'd have a overall battery that can do 1.5 V at 2 A.
7,295 2 11 19. Add a comment. 3. No, you cannot safely power an LED with 5V without a resistor. The resistor is absolutely 100% required. The resistor isn't put there purely on a whim, it's required to set the current based on the supply voltage minus the LED forward voltage and the resistance of the resistor. Share.
\$\begingroup\$ @JerryCoffin All it says to use Arduino as power source, so the assumption is that whatever powers the Arduino, the 5V output on Arduino would be used to power the SIM800 module. And I will have to assume that since the OP has says SIM800 module needs 3.4V and how to make 3.4V with resistors that this is about powering the
It is best to use 4.2V constant voltage charging mode, you can not pay attention to the charging time. Charging with 5V voltage is easy to cause danger of overcharging. The typical lithium battery cell is 3.7V, the voltage when fully charged is 4.2V, the nominal voltage after series connection is only 7.4V, 11.1V, 14.8V
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can i use 4.5 v instead of 5v
