Order Number LMCT. LMCT or LMCT. See NS Package Number T03B. C National Semiconductor Corporation. RRD-B30M Printed in. Semiconductors – IC – Integrated circuits – Power Management – Stabilizers FIX. Image: Click to enlarge. SOT23*LM National Semiconductor => TI. Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. Copyright , Texas Instruments Incorporated.

Author: Shalar Tygozragore
Country: Moldova, Republic of
Language: English (Spanish)
Genre: Business
Published (Last): 15 June 2007
Pages: 479
PDF File Size: 10.32 Mb
ePub File Size: 3.45 Mb
ISBN: 264-9-78248-240-2
Downloads: 12272
Price: Free* [*Free Regsitration Required]
Uploader: Fell

Use an LM if possible – datasheet here.

Good news for China btw: Russell McMahon k 9 Cool Projects for Open Source Hardware. For the years, see 8th millennium. You’ll also have to account for the ripple across the smoothing capacitor. Also, LM has got a lower dropout voltage than and can give a higher current. There are some problems with the design. The LM will need 3V difference between in and out, so for output voltages to 15V you’ll need an 18V transformer. This means your regulator won’t go higher than As you noted you can’t go all the way to 15V, though your calculation contains an error: Views Read Edit View history.

Post Your Answer Discard By clicking “Post Your Answer”, you acknowledge that you have read our updated terms of serviceprivacy policy and cookie policyand that your continued use of the website is subject to these policies.


Home Questions Tags Users Unanswered. I am asking because it doesn’t correspond to the the datasheet:. Ground is connected to your mains! Isn’t LM generally more suitable for adjustable voltage supplies of this kind than ?


Is it normally legal and working, does it mean that we can have any output voltage from any legal input voltage using these IC regulators? The LM78S40 from Fairchild is not part of the 78xx family and does not use the same design. The variable resistor to regulate the output voltage. The is the most common, as its regulated 5-volt supply provides a convenient power source for most TTL components. There is a related line of 79xx devices which are complementary negative voltage regulators.

SOT23*LM National Semiconductor => TI

The 1N for the rectifier is overkill. Wow, when did LM become obsolete? Is this based design correct? It is said to be a regulated power supply with variable DC output V, mA.

There is no need to connect the mains side of the transformer to circuit ground.

Please help improve this article by adding citations to reliable sources. These devices support an input voltage anywhere from around 2.

Some devices provide slightly different voltages than usual, such as the LM78L62 6. The SR from Datel is a full switching power supply module designed as a drop-in replacement for 78xx chipsand not a linear regulator like the 78xx ICs.


Al Kepp 1, 5 19 To protect semicoductor the back polarity problem that you mentioned, connect a diode from output to input usually non conducting. Like Russell says, you can protect the output against overvoltage by placing a power diode between output and input, cathode to the input. Is this design around correct?


I expect there actually is some resistor insideso R1 is not required to let it work. You’ll be able to regulate from 1. January Learn how and when to remove this template message. Here you can calculate ripple as a function of input voltagecapacitance, and load.

The 78xx line are positive voltage regulators: OlinLathrop don’t forget s and s Industrial Electronics and Control.

Possibly lethal, but you may survive it The variable resistor to regulate the output voltage. My life will never be the same again: The 78xx family is commonly used in electronic circuits requiring a regulated power supply due to their ease-of-use and low cost. Notice that this circuit is not isolated from the AC line! I think you answered part of your own question: In other projects Wikimedia Commons. Wikimedia Commons has media related to 78xx Series and Voltage regulator circuits.

The seems to me like a LM with those R1 and R2 added inside.

Previous post: