• Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Time delay for 12V motor using 555 IC

Thread starter #81
Here's one way you could do it :
View attachment 107297
I have not shown all the connections to the 555; just how the output pin 3 drives a transistor.
The transistor can be, for example, a TIP120 or TIP121
The resistor value can be in the 1k to 5k range.
The diode can be, for example, a 1N400x, where x is in the range 1 to 7.
The motor connects to the collector (column 16) and the +ve rail (Y2).

N.B. This layout is shown for simplicity but is not ideal, because motor current is passing through the breadboard connectors (which are intended for low currents only).

Thanks alot!! But currently i have a 2N3904 transistor will it still work?
Also, can i use a 1N4148 diode?
 

alec_t

Well-Known Member
Most Helpful Member
#82
i have a 2N3904 transistor will it still work?
Also, can i use a 1N4148 diode?
Neither of those has a current rating as high as your motor current, so they would get hot and fry.
Get into the habit of reading the datasheets for components you want to use in a circuit, to make sure they can handle the expected voltages and currents.
 
Thread starter #83
Does TIP122 work the same as TIP120/121? Cos my local electronic store doesnt have those 2 in stocks so i bought TIP122 instead. will it work still?
 

alec_t

Well-Known Member
Most Helpful Member
#84
Yes, the TIP122 is fine.
 

alec_t

Well-Known Member
Most Helpful Member
#86
How consistent should the timings be?
 
Thread starter #87
How consistent should the timings be?
Like if i stopped my motor during the duration of the time delay, then if i start my next run immediately after the timing is not around the same.
So it would be best if it could get back around the same duration even after restarting the motor immediately.
 

alec_t

Well-Known Member
Most Helpful Member
#88
Ok. Let's talk numbers. If your target time is 26S, how many seconds either side of that would be 'near enough'?
 
Thread starter #89
Ok. Let's talk numbers. If your target time is 26S, how many seconds either side of that would be 'near enough'?
Its weird tho i know that the values of my caps and resistors should get me around 26secs for the time delay. However, im getting a timedelay of about 20secs. But thats ok tho.
Near i would say about 1-2 secs ?
 
Thread starter #90
Also, my next step of my project is to convert the breadboard circuit and use it on a PCB. How do i do it on a PCB board now, i heard i cannot just copy and arrange the circuit exactly like how i see on the Breadboard, since theres no negative or positive rails.
I currently have 3 types of pcb . One has non plated holes, one has holes that are individually plated and the other pcb has holes plated row by row.
 

Attachments

Thread starter #91
I tried connecting my circuit using the PCB that is plated row by row. and this is how my connections looks like im not sure if this is how we are supposed to connect .
The 2 wires on both sides act as the + and - rails like a breadboard. im not sure if this is how it is supposed to work like . Thank you.
 

Attachments

alec_t

Well-Known Member
Most Helpful Member
#92
The 'row-by-row' board (aka stripboard or Veroboard) is what I would have used.
Do the copper strips of the board in your pic go from top to bottom or from left to right? Whatever, did you remove copper from between the pins of the 555, and elsewhere where needed, to prevent shorting the wrong bits?
 
Thread starter #93
The 'row-by-row' board (aka stripboard or Veroboard) is what I would have used.
Do the copper strips of the board in your pic go from top to bottom or from left to right? Whatever, did you remove copper from between the pins of the 555, and elsewhere where needed, to prevent shorting the wrong bits?
Its going from left to right. I do know that i have to "cut" the copper between the 555. however i dont know where else to remove. but based on the pic i sent and to my breadboard is this how the connection should be like?
 

alec_t

Well-Known Member
Most Helpful Member
#94
From the pic it seems you haven't done the soldering yet? I haven't spotted any obvious mis-wiring.
 
Thread starter #95
From the pic it seems you haven't done the soldering yet? I haven't spotted any obvious mis-wiring.
Yup i havent solder it yet. I wanna make sure i have arranged it properly before soldering. Is my arrangement that i had done the same as my breadboard?
So does this means i can proceed on with the soldering?
Also, if i wanna increase the timing of the time delay in the future , i can just increase the value of the capacitors right??
 

alec_t

Well-Known Member
Most Helpful Member
#96
Get soldering :)
if i wanna increase the timing of the time delay in the future , i can just increase the value of the capacitors right?
Right. Or increase the value of the timing resistor through which the cap charges.
 
Thread starter #97
Get soldering :)

Right. Or increase the value of the timing resistor through which the cap charges.
Oh no it didnt work on the PCB board, thus i put back the components that i took from the breadboard and placed it back on the breadboard. and now my circuit isnt working again.... it just runs non-stop
 
Thread starter #98
Oh no it didnt work on the PCB board, thus i put back the components that i took from the breadboard and placed it back on the breadboard. and now my circuit isnt working again.... it just runs non-stop
It worked once on the PCB board with properly time delay and all, but thn it suddenly didnt work again. why is this happening
 
Thread starter #99
Oh no it didnt work on the PCB board, thus i put back the components that i took from the breadboard and placed it back on the breadboard. and now my circuit isnt working again.... it just runs non-stop
i solved the breadboard issue, however my pcb does not work, it runs non stop im not sure whats wrong.
idk whether is wrong wiring or loose connection
 

JoeJester

Active Member
Show the picture of the component side and the other side of the PCB. Show the picture of the schematic you are currently using.

Make a list of every point you tested and write what you measured.

Do NOT disassemble it. If you do the pictures become worthless.
 

Latest threads

EE World Online Articles

Loading

 
Top