The transistor acts as a current amplifier. Output current = input current x hfe
So to get 1.5A out with hfe=25 you would need at least 60mA input at the base. However I don't recommend drawing any more than 20mA from an ESP32-S3 pin.
So either two pins or a different transistor.
i will see what i can find, i dont have that much transistors at home, i do have multible BC546 transistors capable of 100mA, that sould also be enough for 4 pairs.
Just order a bunch of MOSFETs and call it good.
don't have the time, this needs to be done by monday and i knew i had this lying around and that it will work. but maybe i have mosfets to, this belongs to some stuff i got ones.
Sometimes it helps to rummage through the parts box some more until you find what you need. It's sometimes also quicker than sticking with the first thing you find and trying to make that work.
Having said that, if all you have is a BD135 and some small signal stuff, you could always use one or two small signal transistors to drive the base of the BD135.
You could use a thyristor but it's not a very obvious choice. You'd still have to add a second reset circuit since the thyristor in principle will just keep conducting once you turn it on.
use a transitor to drive the base of the DB135 is fine by me. i think the BC237A that i meantioned earlier will work fine for that.
my circuit design:
the resistors im not quite sure, but i think R2 = 220ohm, as someones said earlier.
But R1 i dont know
Yeah, something like that. You can do the math on the value of R1. Keep into account the Vbe of both the BC237 and BD135.
Simple circuits like these lend themselves very well for SPICE simulation.
Why bother. I have already done everything for you.
it is sometimes quite a chaos when 2 people give 2 different ideas and then i dont know what to focus on sorry.
what is that 1/4W on R1?
and doesn't each led need an individual resistor instead of 1x 20ohm by the looks of it
1/4 Watt resistor or 0.25 Watt
Not really. The LEDs might differ a little in brightness but not enough to notice.
but what about current hogging, what they disscused earlier? wont that face a threat?
i'd rather be safe than kill my school project due to tuesday.
What is that?
post #26 and post#51
Did you read and understand what they mean?
yeah kinda not a full 100% but i undstand that due to tolerance in product there a small difference that cause a "chain reaction" of actions that are not ok.
and being 100% safe by using individual resistors doesn't sound bad to me
Believe me it's not going to happen with a few cheap LEDs but if you want you can use separate resistors of 75 ohms each
