How to get hardware delay of 1s ?

[vamanan]

Hi All,
For one of our product, there are two 48 V pumps used. Both pumps are getting 48V from the same power supply. The inrush current per pump is around 3.14A. Since both pumps are on simultaneously, the inrush current wil shoot up more than 6A. For this reason, I want to make one pump on and after say 1second the second pump has to become on. I am not using any microcontroller or any software. I want to generate the 1second delay using hardware. Can I get the 1s delay using hardware ? anybody help me please.

 

[dmk]

Hardware delay

What do you mean to use exactly? Can you use some ICs? If yes, then you can use 555 (timer) - it allows wide range of delays.

 

[davidgrm]

Re: Hardware delay

are you trying to avoid using electronic components?

 

[jeyaraman]

Re: Hardware delay

You could introduce a suitable pi filter. this will introduce a delay.

Caution: Will dissipate some power, so will warm up.

jeyaraman

 

[vamanan]

Hardware delay

I think I cant use 555 timer. I need to on one pump and after 1 second I want to make on the second pump. But both pump derive power from same power supply. I dont know whether I can use 555 timer or not. Can we get 1 second delay using timer IC. Also I dont want a square wave of 1s period. I want the signal generated after 1 second should be latched continuously.
Jeyaraman, Can I get 1 second delay using PI filter ?

 

[dmk]

Hardware delay

You can realize 1 s delay with 555 and much more.

 

[nandhu015]

Re: Hardware delay

A simple circuit with a resistor, capacitor and transistor which drives a relay will also do the same job.

Regards
Nandhu

 

[Abdul Manan]

Hardware delay

resistor capacitor and transisitor is a good approach

 

[deepuj]

Re: Hardware delay

I also feel using a 555 timer (in a monostable mode) will be an overkill (but will work for sure).

An RC with proper time constant and a circuit that can trigger at the correct level (transistor or op-amp based) should be the best approach.

 

[suresh_kvja]

Hardware delay

you can use IC 555 in Astable mode, TWO transistors (one NPN, other PNP), and TWO relays

Just connect the output of the 555 to the two transistors using some resistance and generate 1sec delay for 555 with 50% duty cycle

 

[KMoffett]

Hardware delay

Guys!...the post ended over two years ago.

Krn