L200C

[Farticus]

Am I missing something when it comes to using a L200C.
The spec says it can deliver up to 2 amps - I can't get more that 700mA out
of one!

I have a stiff source of 32VAC and getting about 40volts DC into the device
after rectification and smooting.
No matter how I configure the damn thing I cannot achieve a 2A output at
12VDC.

I have tried three devices in case one was faulty. A pretty straight forward
cct I thought.

Any ideas?

 

[Trevor Wilson]

"Farticus" <localhost@127.0.0.1> wrote in message
news:tRbNk.8736$sc2.2483@news-server.bigpond.net.au...

Am I missing something when it comes to using a L200C.
The spec says it can deliver up to 2 amps - I can't get more that 700mA
out of one!

I have a stiff source of 32VAC and getting about 40volts DC into the
device after rectification and smooting.
No matter how I configure the damn thing I cannot achieve a 2A output at
12VDC.

I have tried three devices in case one was faulty. A pretty straight
forward cct I thought.

Any ideas?

**What is the thermal resistance of your heat sink?

Also, I suggest you examine Figure 3 in this spec sheet:

http://www.stmicroelectronics.com/stonline/products/literature/ds/1318.pdf

You're going to need to shed some Volts somewhere.


--
Trevor Wilson
www.rageaudio.com.au

 

[Phil Allison]

"Trevor Wilson"

"Farticus"
Am I missing something when it comes to using a L200C.
The spec says it can deliver up to 2 amps - I can't get more that 700mA
out of one!

I have a stiff source of 32VAC and getting about 40volts DC into the
device after rectification and smooting.
No matter how I configure the damn thing I cannot achieve a 2A output at
12VDC.

I have tried three devices in case one was faulty. A pretty straight
forward cct I thought.

Any ideas?

**What is the thermal resistance of your heat sink?

Also, I suggest you examine Figure 3 in this spec sheet:

http://www.stmicroelectronics.com/stonline/products/literature/ds/1318.pdf

You're going to need to shed some Volts somewhere.

** Absobloominlutely.

You are asking the poor thing to dissipate over 60 watts !!!

The input voltage must be no more than 25V for any chance.




...... Phil

 

[Farticus]

"Phil Allison" <philallison@tpg.com.au> wrote in message
news:6mlnfdFherinU1@mid.individual.net...

"Trevor Wilson"
"Farticus"
Am I missing something when it comes to using a L200C.
The spec says it can deliver up to 2 amps - I can't get more that 700mA
out of one!

I have a stiff source of 32VAC and getting about 40volts DC into the
device after rectification and smooting.
No matter how I configure the damn thing I cannot achieve a 2A output at
12VDC.

I have tried three devices in case one was faulty. A pretty straight
forward cct I thought.

Any ideas?

**What is the thermal resistance of your heat sink?

Also, I suggest you examine Figure 3 in this spec sheet:

http://www.stmicroelectronics.com/stonline/products/literature/ds/1318.pdf

You're going to need to shed some Volts somewhere.


** Absobloominlutely.

You are asking the poor thing to dissipate over 60 watts !!!

The input voltage must be no more than 25V for any chance.




..... Phil

I was missing something alright - attention to detail!!
I need to create a few power supplies with 32VAC input capable of 12VDC/2A
out.
A quick reflection brought to mind the L200C which I used some years ago.
So, a quick scan of the spec sheet and my eyes fell on the opening
paragraphs, Vi=40; Vimax=60; Dropout 32; Adjustable and 2Amps.
Aha, just the thing for my application. Without further ado, I hashed up a
birdsnest test cct, hence the no-go situation.

Too much on the mind? Taking things for granted? - no excuses, I cocked up!

Thanks for pointing out the obvious, as per Figure 3. I now have a triac in
front of a bridge rectifier to power up the L200C at about 18VDC,
it adjusts perfectly to 12V and limits beautifully at 2A.

Regards.