circuit for a few milliseconds time delay?

greets

I need a simple circuit that will insert a small time delay (25-100 or so) ms between a button push/release and a LED turning on/off.

I tried a few ones like this:

I've used a BC337 transistor instead and played around with different value resistors and capacitors, but I only get a gradual increase in current flow and gradual decrease. I want the led to go on and off like a digital signal, 0 to 1 to 0.

Should I instead use a logic level mosfet, or is there a simpler solution?

naut: Should I instead use a logic level mosfet, or is there a simpler solution?

In a Arduino forum we'd say "use software"...

Not doing stuff like this in hardware is the whole point of microcontrollers.

I know how to do this with code but I don't want to rely on micro-controllers every time I need to do something simple.

I need a simple circuit that will insert a small time delay (25-100 or so) ms between a button push/release and a LED turning on/off

Not sure what do you expect, but if you are keen on playing with transistors - this may work - the led switches on 300ms after the button is pressed and turns off about 100ms after the button is released.

…I don’t want to rely on micro-controllers every time I need to do something simple

You are right, you do not need 40000 transistors in order to blink a LED, just couple of them is enough :slight_smile:

Your circuit will be good at burning out the push-switch and briefly short-circuiting the supply.

You need to limit the current through the switch into the 1000uF capacitor with a resistor, otherwise it will simply take all the available current and "crowbar" the supply rail down to 0V.

naut: I know how to do this with code but I don't want to rely on micro-controllers every time I need to do something simple.

Google resistor-capacitor time constant.

It's very good knowledge to have when constructing your own capacitive touch sensors or when you want to lengthen out a sensor blip or even help to understand using a led and resistor as a light sensor.

Capacitance between objects is in its own way as, possibly more, marvelous as interactions between magnets and conductors. Resistors and inductors just make it better.

Digital is okay but at times alone it's like monochrome pointillism.

Later on start looking for oscillator circuits.

naut: I know how to do this with code but I don't want to rely on micro-controllers every time I need to do something simple.

Yes, but:

a) This is an Arduino forum. b) I typed "switch del" into google and had "switch delay circuit" as a suggestion before I even finished typing "delay".

Arduino that lets us bridge real world and analog to digital chips and PC's.

a) This is an Arduino forum.

Arduino is an open-source electronics prototyping platform based on flexible, easy-to-use hardware and software. It's intended for artists, designers, hobbyists, and anyone interested in creating interactive objects or environments.

MCU is just a part of an interactive object or an environment. The biggest issue I see today is that everybody (or most young people I know) is/are typing a code (while the biggest issue they face is to find the right cable), without knowing how the stuff works. Therefore I do appreciate people who are interested in "electronics" as well :)