| sss |
does anybody used this chip before?
i'm using it right now for my car smps and its great |
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| 2pist |
| I'm using a NE556 dual timer. Cheap and works great. I use 1/2 as an oscillator and the other 1/2 as pwm with a 30v zener tied from the negative rail to pin 11 on the 556 for regulation. |
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| himanshuraval |
| quote: | Originally posted by sss
does anybody used this chip before?
i'm using it right now for my car smps and its great |
hi sss
put your full working schematic here with thanks |
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| himanshuraval |
| quote: | Originally posted by 2pist
I'm using a NE556 dual timer. Cheap and works great. I use 1/2 as an oscillator and the other 1/2 as pwm with a 30v zener tied from the negative rail to pin 11 on the 556 for regulation. |
hi 2pist
you also put here your NE556 based schematic please |
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| sss |
hi himanshuraval
i'll put a schematic when i'll finish it :)
gotta design more things like remote and stuff like that |
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| N-Channel |
Hi SSS,
Unitrode's (now TI's) numbering of chips goes something like this:
UC1XXX - Mil-Spec (-55C to +125C)
UC2XXX - Industrial (-40C to + 105C)
UC3XXX - Consumer (0C to +70C)
Hence, the UC 2825 is the industrial version of the UC3825. The Mil-Spec version would be the UC1825.
Basically, this series of PWM chips is pin-for-pin compatible with Motorola's (Now ON's) MC34025 (0C to +70C) and MC33025 (-40C to +105C) dual-ended PWM IC with 1MHZ oscillator. Good for off-line and DC-DC push-pull, half- and full-bridge topologies. Good bandwidth on the error amp, too. Can be used as either voltage-mode or current-mode.
Great chip! I have used them in 42-14V DC-DC Convcerters. A BIG :bigeyes: improvement over the SG1525/2525/3525 (400kHz max) voltage mode-only PWM ICs.
Hope this insight helps!
'73,
Steve, N8XO |
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| agent.5 |
I found this SMPS schematic using UC3825 (the military version of 2825). It looks very clean and quite low in part counts.
What does he mean when he say
"Transformer: 4.5 + 4.5 turns : 120 turns (that's core-specific of course)"
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| sss |
4.5+4.5 turns mean 4.5 turns centre tap and another 4.5 turns
(2 primary coils with 4.5 turns each-push pull design)
i gues 120 is the number of turns for the secondary |
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| N-Channel |
agent.5,
I think you have it backward: the UC3825 is the consumer (commercial) version of the UC2825. And, the UC1825 is the Mil-Spec version. As for the schematic, I would be interested in seeing it.
Steve |
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| Tolik |
Hi SSS,
Can I see your UC2825 schematic ? |
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