switch on delay

[senderj]

I know nothing about circuit design and electronics, but starting to DIY a UcD amp. I am thinking of making use of the on/off switch of the amp module to make a switch on delay for the amp. I guess a simple RC timer can serve the purpose and 1 minute is good enough for me. But I don't know how to design a circuit for it. Can somebody draft me a suggestion?

I know there are many output delay in the market. They use relay to connect/disconnect the output to speaker, which I think would affect the sound quality. Since UcD has an on/off pin next to the input, it will be a better place to add a delay for protection. What do you think?

[peranders]

Have you checked Hypex´softstarter?

http://www.hypex.nl/docs/softstart.pdf

[classd4sure]

Originally posted by senderj
I know nothing about circuit design and electronics, but starting to DIY a UcD amp. I am thinking of making use of the on/off switch of the amp module to make a switch on delay for the amp. I guess a simple RC timer can serve the purpose and 1 minute is good enough for me. But I don't know how to design a circuit for it. Can somebody draft me a suggestion?

I know there are many output delay in the market. They use relay to connect/disconnect the output to speaker, which I think would affect the sound quality. Since UcD has an on/off pin next to the input, it will be a better place to add a delay for protection. What do you think?

To get this straight, you want to delay the turn on of the amp for a minute, and that's it?

First of all, unless you're powering it with a lab rat driven flywheel, there's no possible reason for such a long delay.

Second, the required turn on delay for the module is in fact in-built.

Third, if the intended purpose for this rather long delay was to operate in conjuction with any kind of a soft start circuit based on series resistance in the primary winding, you'd likely have a fire on your hands.

Wire module according to instructions and don't get too creative with it unless you really understand it, and it will last a loooong time for you.

[senderj]

Originally posted by classd4sure



To get this straight, you want to delay the turn on of the amp for a minute, and that's it?

First of all, unless you're powering it with a lab rat driven flywheel, there's no possible reason for such a long delay.

Second, the required turn on delay for the module is in fact in-built.

Third, if the intended purpose for this rather long delay was to operate in conjuction with any kind of a soft start circuit based on series resistance in the primary winding, you'd likely have a fire on your hands.

Wire module according to instructions and don't get too creative with it unless you really understand it, and it will last a loooong time for you.

Classd4sure,

thanks for the reply.

The reason I thought of this idea is because my GG pre has up to 24V DC at the output at the 11th second after power on, then to-24VDC afterward. So I only turn on my power amp 1 minute after turning on the pre. With a 1-minute delay in UcD, I don't have to count the time myself.

By "in-built", did you mean there is one already in the module of UcD. I may have missed it if it was mentioned in UcD site. Please point me to the page if possible.

Thanks again.

[rpapps]

I think I would be looking at why the pre-amp has 24 volts on its output at any time.
Cheers
Rob

[classd4sure]

Originally posted by senderj


Classd4sure,

thanks for the reply.

The reason I thought of this idea is because my GG pre has up to 24V DC at the output at the 11th second after power on, then to-24VDC afterward. So I only turn on my power amp 1 minute after turning on the pre. With a 1-minute delay in UcD, I don't have to count the time myself.

By "in-built", did you mean there is one already in the module of UcD. I may have missed it if it was mentioned in UcD site. Please point me to the page if possible.

Thanks again.

There is and it's good for about a second or two. Nothing written about it, it's just there to ensure the bootstrap voltage comes up before the output gets enabled.

I'd be more concerned with the DC on your pre-amp too.

[AndrewT]

Hi,
instead of delaying the power amp switch on, how about muting the pre-amp output?

Even with sequential switch on and off an instant mute and progressive unmuting sounds nice.

But I agree with the others, investigate the pre-amp DC malady.

[classd4sure]

I'd go with that too, seems such circuits are sometimes called "soft starts" which can be rather confusing with the usual in-rush limiter.

BTW it is great practice to turn the pre-amp on first and off last. My soundcard audiodock has such mute/softstart features and it doesn't matter if you happen to turn the PC off first there's a pretty good snap audible over the amp.

The neat thing is, it sounds just like relay contacts... reaaaally big ones.

[Original Burnedfingers]

Vellerman makes a nice kit that you could use in your application.
The K4700 provides a 6 second delay with the standard kit parts and will provide more delay with a little modification. By changing to a larger cap in the C11 position the delay can be made longer.
This is a speaker protection kit but will work well on your preamp since it satisfies the need to monitor DC and a delay factor.

[Original Burnedfingers]

Make that Velleman