555 chip based delay

[niiico]

Hi,

I'm planning to make a delay circuit to connect speakers output in a 41hz.com AMP4 after 1s. There is a relay on board but it closes after only .3s and I get a big "thump" in the speakers. I put a switch on the command and if I close it after 1s, no thump. My problem is that I can solder kits but I'm a total newbie in electronics.

So, I want to create a circuit to close the relay after 1s. I found some examples of 555 chip usage as a delay but i don't know if it can drive directly the relay or if I need a transistor. All I know is that the relay closes at about 17V and that I can power the 555 chip with 20V (this seems to much) or 9V or even 5V. And if needed, what kind of transistor ?

The delay schema is here : http://555-timer.clarkson-uk.com/operation/delay.html

and here : http://www.technologystudent.com/elec1/5554.htm

Thank you for your help.

 

[Nordic]

Hey Nico, look in the PSU section, there is a newish thread about a 12 - 24V preregulated supply... on the second page is what you were looking for... an easy relay board, all you need to change is one resistor to accommodate your power supply. With supply under 15V youcan bypass this resistor with wire.

 

[niiico]

Thank you,

but what software (open source?) can I use to read the schema?

 

[Nordic]

The free version of Eagle

 

[niiico]

You reply faster than your shadow!

Thank you

 

[Nordic]

Avec plaisir!

 

[niiico]

Hey Nico, look in the PSU section, there is a newish thread about a 12 - 24V preregulated supply... on the second page is what you were looking for... an easy relay board, all you need to change is one resistor to accommodate your power supply. With supply under 15V youcan bypass this resistor with wire.

Just one more question : my supply will be 24V. Is the resistor big enough or should I put another value?