Can I use a pull-up resistor to increase the gate voltage to something closer to 5V? From the tutorials I’ve read and watched, I thought this would be fine? Try one of these http: Mar 6, Messages: It always takes longer than you expect, even when you take into account Hofstadter’s Law. The gate voltage to “turn on” a mosfet is Vgs gate to source.

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This meant that the strike latch negative terminal went straight to ground.

2SJ P-channel Mosfet | Jaycar Electronics

Parcel Lockers We deliver to parcel lockers around Australia. Check the datasheet if using a different MOSFET, as they might be in a different order, and some might have different ratings.

These circuits are probably all you would need for a relay coil, or even jaycag speaker generating tones, as the power only needs to be applied one way.

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N-MOSFET Driver & Output Module for Arduino

Share This Page Tweet. If you have something that simply needs to be on or off, then jayycar transistor will probably do the job. Perfect for controlling that set of traffic lights mounted in your living room! No, create an account now.

Contact the Techstore should you require more details. That all sounds perfect, but I need a solution sometime tonight, which is why this is so urgent. While it might look that the H-bridge IC is the much better solution, there are some limitations. In fact, the BUZ71 is a very marginal device, but the original IRF will probably work for your app if you wire it up properly, even though not a logic-level device. You could lay them out on a breadboard for prototyping, and then build a custom shield if you need a more finished solution.


If you use an N-channel high side, the source is connected to 12V and your gate is 3. If you need a very high frequency PWM, a transistor will usually be a better choice, as it can switch faster than a H-bridge. Google says it is configurable and you may have to activate the appropriate pull-down resistors.

An Uno’s pins can’t go any higher than 5. Your name or email address: MarkT Brattain Member Posts: Next working day Selected Metro Areas orders placed before 2: If you left jaycwr floating, then simply touching the gate with your finger will transfer enough charge to keep it conducting.

I’d try it and see what happens. If you want to drive something like a motor, solenoid, relay or even a speaker, mosffet you’ll need extra components.

Why do MOSFETs hate me? | OCAU Forums

jqycar I get “a few” of my components from jaycar unless it’s a case of “I need a 63 ohm resistor and a jaycag. For some reason I had to swap the Drain line from the strike latch negative terminal to the 12V supply negative wire.

I’ve been working jayycar this all day, and am about to tear my hair out. Discussing NPN transistors for now, while MOSFETs typically work off the voltage applied to their gate compared with their source VGSa bipolar transistor depends on the current flowing into the base and out of the emitterand permits a proportional current to flow into the collector.


Works brilliantly for automotive projects such as switching high-power 12V lights and high wattage LEDs.

Call our Techstore on Mar 6, Messages: On the rPI side, put say a resistor to limit current though the opto’s diode – ohm should give you approx 5mA on common optos. Look for the voltage the quote when they quote the on resistance. Another thing that can occur is that if the two left switches for example were to be connected at the same time, the supply would be short circuited. Bipolar transistors are also more sensitive to voltage spikes which can occur when a motor is turned offso require a ‘snubber’ diode to shunt jsycar spike away from the transistor.

The Arduino pins marked below are the connections used in the demo circuit. They are dead cheap, and can come in 4 pin DIP devices to make handling easy.