[darlington optocoupler]

Ginji,

Are you sure it is broken? This is a component that does not break down under normal conditions.

Ante

[Switching power supply]

audioguru,

I still think the Darlington is the better choice. We are talking about pulses that are of different length (PWM) and between the pulses the transistor

[ZP 1311 G M detector]

I need a datasheet and/or application note for Philips ZP 1311 G/M detector, it's an old one I know.

Thanks!

Ante

[darlington optocoupler]

ginji,

What is the application?

Ante

[Switching power supply]

audioguru,

You stated,

[Switching power supply]

audioguru vainajala,

The collector outputs in the 494 can sink 200mA maximum, will this suffice as base current for three transistors? What makes you think that a Darlington can

[Switching power supply]

Vainajala audioguru,

I think it

[Help please, Need 12 V DC Power Supply for ATX Mainboard]

Andy,

The ATX main board or motherboard uses several different voltages one of these is +12Volts. Your computer won

[Switching power supply]

vainajala,

Try to use a 2.2k for R3. As far as I can see the emitters and collectors of the TL 494 is correctly connected. With the change of R3 the efficiency should improve a bit and the heat in R2 will be reduced. Have you access to a scope? I would be useful to see how Q1 performs and possibly make some minor changes to improve the efficiency.

Ante ::)

[New Articles added]

Mixos,

This is mounting to quite a library!
Good Work!

Ante ::)

[Switching power supply]

vainajala,

Looks very nice, please keep us posted! ;D

Ante ::)

[Supa Dupa Basic Timed Latched Relay]

Laet,

I suggest that you connect the rely on the other side of the transistor to start with.

Ante ::)

[batteries]

audioguru, shekhar,

I don

[Supa Dupa Basic Timed Latched Relay]

Laet,

First, are you sure the coil resistance is 6.7 Ohms? This will be one HOT relay, nearly 30W it seems too much ???.

Now that we know the purpose of the relay it

[batteries]

shekhar,

What I mean is the length and the diameter of a cell.

Ante ::)

[0-30 Vdc Stabilized Power Supply]

Kain,

Everybody makes mistakes sometimes, don

[batteries]

shekhar,

You don

[0-30 Vdc Stabilized Power Supply]

audioguru,

I

[0-30 Vdc Stabilized Power Supply]

Kain,

With no external divider the 3V battery will show

[Battery back-up]

Han,

This is the easiest way I can think of, but maybe you had something different in mind?

Ante ::)

[0-30 Vdc Stabilized Power Supply]

Kain,

Yes it

[Battery back-up]

HAN,

What kind of battery do you have 12V or 6V and what

[0-30 Vdc Stabilized Power Supply]

Kain,

There is one more thing to consider, these meters can usually not be powered from the same supply as you measure on. This is not a big problem, there are several ways to fix this.

Ante ::)

[Battery back-up]

HANIFF,

Welcome to the community.
I need to know some more details. What is the

[Supa Dupa Basic Timed Latched Relay]

audioguru,

So that