uPC1237/NTE7100

[zeonrider]

2

[zeonrider]

3

Regards zeoN_Rider

[Nordic]

Hallo loek, I replied to your e-mail...

Nice layout Zeon... interesting the dual relay...

May I ask why you chose that over the single relay...? also does it still fall within the chip's output rateing to actualy handle two relays?

[zeonrider]

1.I, like simetry, & simple I, have it,
2.yes!

Regards zeoN_Rider

[jaycee]

Personally i've never seen the point of using such IC's in a DIY design. Commercial offerings use them in order to save parts count and cost, but it's much better to do something discrete especially as these IC's often go obsolete.

These days it's often done discrete anyway, but usually strictly as a detector - this is then fed to the amp's microcontroller which controls the speaker protect relay and/or the power relay.

[loek]

I found them overhere Nico.
Thanks Jan and Nico for the help finding those chips.
Regards, Loek

[d3imlay]

Originally posted by zeonrider
3

Zeon,

Nice work. I'm working on a similar project and have found that the voltage at pin 2 will not exceed a few volts which would allow for a lower voltage cap. Also, why use 2 in series when bipoars are available? I always subscribe to the notion that unused input pins on a chip are tied to ground or V+ to avoid noise issues. On mine I have a zero ohm resistor going to ground on pin1. I also brought out pin 1 to a terminal, through another zero ohm resistor so that it could be used at a later date in case I want to add an over current sense.

Regards zeoN_Rider

Originally posted by jaycee
Personally i've never seen the point of using such IC's in a DIY design. Commercial offerings use them in order to save parts count and cost, but it's much better to do something discrete especially as these IC's often go obsolete.

These days it's often done discrete anyway, but usually strictly as a detector - this is then fed to the amp's microcontroller which controls the speaker protect relay and/or the power relay.

Jaycee

I agree with you that discreet would be desirable. In my application I have limited space for a board. I'm banking on this chip being available for a while since NTE has an equivalent.

[Nordic]

buy 5 and stick them to the inside of the case, like spare fuses if you are paranoid...

[jan.didden]

Originally posted by jaycee
[snip]Commercial offerings use them in order to save parts count and cost, but it's much better to do something discrete especially as these IC's often go obsolete.[snip]

Obsolescense is often a problem, although these chips, because a lot of manufacturers use them - will probably stick around some time.

In what way would a discrete circuit be better?

Jan Didden

[jaycee]

Originally posted by janneman

In what way would a discrete circuit be better?

Small-signal transistors suitable for the job will always be available