LM358P LM358 Dual Operational Amplifier IC Om-Amp DIP-8 (Pack of 50pcs)

Used them to turn strip lights on and off in an HO scale coach with a magnet. They were hooked up directly to reed switches with a watch battery as power. One reed would turn it on, and the other off. Worked great until I lost the magnet, but then replaced it with another magnet. These can handle the job.

I used these to power up son LED’s in my circuit and works great!

Let’s be real—there are sleeker, more efficient transistors out there… but the TIP31C? It’s the Chevy 350 small-block of general-purpose BJTs. It’s rugged, it’s simple, and it’ll push through heat, current, and amateur mistakes like a champ.I grabbed a pack of these to throw into:A DIY audio amplifier project (classic transistor push-pull),A linear power supply I was repairing,And even a high-power LED dimmer test circuit—and yep, it handled it all just fine.The C variant means it’s the high-voltage version of the TIP31 line—can handle up to 100V and 3A if you’ve got a decent heat sink strapped on. Great for switching, signal amplification, and good ol' analog control circuits. If you’re into learning by building, this one’s your friend.Why It Slaps:TO-220 package = easy to mount, easy to cool, breadboard-friendly (with a breakout)Handles high voltage & current loads without blinking (with proper thermal planning)Works great for PWM, amplifiers, relays, motors, and LED banksCheap and available—perfect for experimenting and prototypingWhat Could Be Better:Needs a good heat sink at anything over 1A—this thing will get toastyBJT means base current draw—if you're coming from MOSFETs, plan your resistorsNo extras in the packaging—no mounting hardware, no datasheet (but hey, it’s online)TL;DR:The ALLECIN TIP31C is a tough, no-frills NPN silicon power transistor for your mid-to-high power needs. It’s not fancy. It’s not surface mount. But it’s reliable, affordable, and ready for abuse—which makes it a perfect staple for DIY electronics and educational builds.It’s the kind of transistor that forgives your mistakes and teaches you something.

Tested all 10 for gate threshold and Rdson after receiving counterfeit product from different vendor. These seem genuine and all work just fine.

I'm uncertain if these are genuinely 2N5457 transistors, but they work for what I need.

I read some ppl mentioned bad units. It might not. You need to discharge Gate first before test Source and Drain. Simply connect Gate and Source. BTW, from left to right when facing the print word side:1️⃣ Gate (to Pi GPIO pin)2️⃣ Drain (to Led-)3️⃣ Source (to 12v+)BTW: Led+ to 12v+

The one I tried worked. I had to look up the pin-out -- with leads down and the angled sides facing you (the flat side facing away from you), the left is +5VDC, middle is GND and the right is the output. Nominal output is 2.5VDC with no magnetic field. The direction of the output changed when the magnet was reversed. With just one 1/4" diameter disk magnet, the voltage range was 4.24V and the low was 0.80V with the magnet at the sensor; with two magnets the low went to 0.75V, the high was the same.With the two magnets, the output changed by 0.001V about 6 inches but remained that way until about 1/2 inch where the voltage was about 2.63 volts -- 0.13V change. A 3-inch stack of magnets was 2.68V. A 1 inch disk magnet gave 3.25V at 1/2 inch and 2.75V at 1 inch distance. At 2 inches the 1-inch magnet gave a change of 0.04V from the 2.5V nominal.

The specs show they are rated at 95 Watts dissipation. I bolted two of mine to a giant heat sink, and ran 15 Volts at 1 Amp or 15 Watts through the unit. It got so hot, it burned my finger tip. The heat sink was still cold. I then ran it up to 30 Watts, the MosFet promptly short circuited. The heat sink was still cold.I don't know what these are. I don't think they can handle 30 Amps either. They were cheap enough, I'm just going to junk them.