does these two IC do the same?

Thread Starter

christiannielsen

Joined Jun 30, 2019
389
I have two IC's. Please see pictures.

Does these two do the same?
Im not sure I find the right datasheet for one of them. I'd like to know what you think/know it is.
fullsizeoutput_30f.jpeg fullsizeoutput_310.jpeg

thank you in advance, this is a great forum
 

ericgibbs

Joined Jan 29, 2010
21,439
hi C,
Note, if this 555 is going to be used on the PIR project, the PIR only puts out 0v to +3v.
The 7555 will work over a range of 2V to 18V,,,, the NE555 is only 5V to 15V, so the 7555 is one that will work with the PIR.
E
 

Thread Starter

christiannielsen

Joined Jun 30, 2019
389
thank you, there sure is a lot to pay attention to.

All sorts of problems appears constantly. For example I wanted to connect a solenoid to the mosfet drain. After the mosfet switched on the solenoid became unstable and I never really could measure 6 volts on the drain as it should put out to the solenoid. So I predict a lot of questions is to be asked in here in the near future.

how do you store your mosfets? I was wondering if my mosfets have become wacki by being stored in this:76038_s_(300).jpg
 

ericgibbs

Joined Jan 29, 2010
21,439
hi C,
My strongest advice for your future electronics hobby development, would be to get a simple drawing program, so that you can show the rest us, the circuit that is giving you a problem.

Note: when switching an Inductive load [ relay coil, solenoid etc] with a semiconductor device, [ transistor, MOSFET etc] it is important that you connect some form of suppression component across the inductive load.
The most common suppression is a diode, some use a resistor and a low value capacitor in series.

When you switch Off fast, a current flowing in an inductor it creates a high 'back EMF voltage, this is Lenz's Law.... V = - L di/dt Look it up.

E

Added:
https://www.expresspcb.com/free-cad-software/
 

Dodgydave

Joined Jun 22, 2012
11,395
The 7555 is a cmos version, it has a better voltage range, i would stock up on these and keep them in an Anti-static tube.


If you want to store them in your cabinet, you need Anti-static foam..



Antistatic-transparent-ic-tube-packing-ESD-pvc.jpg
 
Last edited:

dl324

Joined Mar 30, 2015
18,326
how do you store your mosfets? I was wondering if my mosfets have become wacki by being stored in this:
The drawers doesn't look like antistatic me.

I store my MOSFETs in the original packaging (or whatever they were shipped in - assuming it was antistatic material). If they're used for prototyping and can be reused, I store them in various antistatic material. It's not a good idea to put parts that have been used back with unused parts.
 

dl324

Joined Mar 30, 2015
18,326
Will this tester be able to test the mosfets for being damaged?
Not likely. Some damaged parts will still function, but exhibit specs outside of manufacturer limits.

I have some 2N7000 that were damaged and still function (sort of). They have higher leakage currents than good devices.
 
Top