2015年10月17日 · The MIDI specification calls for a high-speed optocoupler. which the PC123 is not. At the 5 mA specified for the MIDI current loop, the PC123 has a guaranteed current transfer ratio of at least 50 %. This means that to get a 5 V signal out, you need at load resistor (Rd above) of at least 5V/2.5mA = 2 kΩ.

2020年8月25日 · Here's a quick simulation in LTspice: So if you want a relay afterwards, you could use it, since the voltage across the cap, even if not zero, will be, most probably, below the threshold.

2019年3月28日 · Figure 1. LED IV curves. Source: LED current-voltage relationship. Your opto-coupler uses an infrared LED. When you connect this directly in parallel with any other colour LED the voltage across the LEDs drops to that of the lowest one - the infrared in this case.

2015年5月24日 · At 31250 baud, one bit has a length of 32 µs. For reliable operation, the raise/fall times of your optocoupler's output must be much less than that; the MIDI specification recommends less than 2 µs.

2015年4月17日 · I'm building a MIDI IN to serial port RX cicruit (for Raspberry Pi, or Arduino, or anything else...) using a 6N138 optoisolator. But I find many different circuits, I don't know why there are so

2016年10月26日 · I have MIDI keyboard (MIDI interface, not MIDI through USB) and want to make it to control 12 colored lights (LEDs probably as incandescent bulbs may not be fast enough to follow the music), one per

2018年4月11日 · Where I use to work at we detected 230 VAC with a 4 pin H11AA814 AC optocoupler. Use a 220K 1/4W resistor to get 1.045 mA of current at 0.24 watts, which is plenty enough to sense AC.

With the parts in the mail, haven't had the time to test, but the simple question: will this work, or what improvements are needed? What it's supposed to do: a MOSFET switch for 12V, 0.5-3A loads,

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