The 1k resistor is a pull-down resistor. Not the weakest one of that, but that's okay. It is meant to pull the base of the transistor to a known state (ground) when the control signal is missing/open/high input. To prevent a floating signal or even leakage current from turning the transistor on, to make sure the strike doesn't open or engage ...

Nov 18, 2022 · \$\begingroup\$ 1: you have to check both CC1 and CC2, both pins have their own resistor, and one can be 0V (connected to the <1k resistor in the active cable), while the other one is connected to the other side. 2: with an USB A to C cable, you are supposed to follow these rules, but allmost all sources allow devices to draw 500mA without the ...

Lets say you go for 10mA, and have a red LED with a VF of 2V. I'm assuming the the Rpi supply voltage is 3.3V, so the pin output high will be 3.3V. The resistor goes in series with the LED. The voltage across the resistor will be the supply voltage minus the LED Vf. With this information, to calculate the resistor value we use Ohm's law:

Aug 14, 2020 · Assuming the switch is not a shorting type (most are break before make), the R1 1K resistor is not necessary (and could be harmful to noise margin if the value of R7 was too low relative to 1K), however you may wish to have a resistor between pin 9 and SEL of a few K to help protect the IC against ESD that could come through the switch.

Mar 17, 2015 · The 1K resistors limit how much current flows through the LEDs so they don't blow. The 10K resistors limit how much current flows into the capacitors, setting the "time constant" of the charging of the capacitors. $$ \tau = RC $$ This combination of resistor and capacitor is what sets how fast the LEDs flash.

Feb 21, 2021 · But if you connect it to a load with an impedance of less than a few thousand ohms (say some 8-ohm speakers) then the voltage at the output will be much lower, most of the power will go into heating those two 1k resistors, and very little of it will go into the load.

Aug 17, 2023 · If you are making UFP (Upstream Facing Port), which means "consuming device", you need 5.1k pull-downs on both CC wires. The max current to take is determined by provider (host) capability, which is "advertised" by means of PULL-UPs on host/provider side. If the pull-up is 56k, no more than 500/900 mA can be taken by consumer.

Well yes, you can combine in series two 1k resistor in order to make a 2k one. However, if you want to draw some current from this new voltage point, you rather use a linear voltage regulator such as 7805 or a LM317 combined with resistor. A little tips about resistors in series :

May 6, 2018 · Why did a 1k resistor solve my problem? I wanted to control a 3 wire computer fan with PWM(25 kHz 50% duty) from my Arduino NANO pin 10. My Circuit was very simple. I had an IRLB8721F N-Channel MOSFETn a dell HU843-A00(delta ) Chassis fan, a 4148 flyback diode and a pc power supply which I rigged to output 12v.

Mar 24, 2023 · Adding a 1K or 500R resistor between the output and ground with ±5V supplies will draw ±5mA or ±10mA at full swing. If your circuit already draws a few milliamps into the load or feedback network at full swing then there's no point in adding that extra resistance.