LM Fluid Detector. The is a monolithic bipolar integrated circuit designed for use in fluid detection systems The circuit is ideal for detecting the presence. LM datasheet, LM circuit, LM data sheet: NSC – Fluid Detector, alldatasheet, datasheet, Datasheet search site for Electronic Components and. LM Datasheet, LM PDF, LM Data sheet, LM manual, LM pdf, LM, datenblatt, Electronics LM, alldatasheet, free, datasheet.

Author: Dujind Bak
Country: Nepal
Language: English (Spanish)
Genre: Automotive
Published (Last): 20 March 2012
Pages: 406
PDF File Size: 5.95 Mb
ePub File Size: 6.23 Mb
ISBN: 217-5-75566-261-6
Downloads: 73630
Price: Free* [*Free Regsitration Required]
Uploader: Tacage

With the give value of C1 the frequency will be around 6KHz. A method for activating a relay when the liquid level exceeds a predetermined level is shown here.

The circuit diagram for the above said scheme is shown below. Loud speakers can be driven only by using AC signals and a DC signal will not produce any sound out of the speaker. Capacitor Cb couples the oscillator output to the probe and it ensures that no DC signal is applied to the probe. You have to connect the tweeter between Pin No12 and Vcc through suitable resistance. Pin 9 of the IC can be used to solve this problem.

Hi Challa it is meant for normal water, hence can be used for our domestic use to control over head tank water level.

(PDF) LM1830 Datasheet download

Resistor R3 limits the collector current of the internal transistor while resistor R4 provides protection to the IC from transients. Usage of AC signal for detection datashedt electrolysis and this makes the probes long lasting.

Low liquid level indicator LED. Low liquid level warning audio. For non metal tanks fix a small metal contactor at its bottom level and ground it.

High liquid level activated switch. Hai, Can it be used for Water level indicator in a Over head Tank. Capacitor Ct sets the frequency of the internal oscillator. The probe used here can be any metal rod with size and shape of your choice.


HTTP This page has been moved

Your email address will not be published. The load that is the relay is connected at the collector of Q1. The circuit diagram of a liquid level indicator using loud speaker at its output is shown below. The probe must be placed at the level you want to monitor.

LM1830 Datasheet PDF

Manufactured by National Semiconductors, the LM can detect the presence or absence of polar fluids. When the probe is not touching the water it equal to an open circuit situation and surely the probe resistance will be many M ohms and it is greater than the R ref 13K. Liquid level indicator admin October 12, 11 Comments. The circuit is similar to the first circuit except that the LED is replaced by a loud speaker and the load current limiting resistor is changed from 1.

Achei fantastico o site. A capacitor connected from this pin to ground will keep the internal output transistor steadily ON whenever the probe resistance goes higher than the reference resistor. Hi, can this sensor circuit be used to detect diesel fuel? Hi Rohit Pin No 5 is oscillator out put for external reference resistance. There is no problem in driving the LED using AC signal and this method is very useful when it comes to use a loud speaker as the indicator.

Please refer to the second circuit above. You may also like: DC voltage is required for driving the relay and AC voltage cannot be used here just like what we did in the case of LED and speaker. Level indicator using external reference resistor. The LED connected to the collector between pin 12 and Vcc is driven. The load connected through the relay whether pump, lamp, alarm, solenoid valve or anything is driven. The tank must be made of metal and it should be properly grounded.


The oscillators output is directly available at pin 5 and the Rx connects the oscillator output to the probe through the blocking capacitor. The circuit of a low liquid level indicator with LED is shown above. When the probe to ground resistance goes above the R ref the oscillator output is coupled to the base of the internal output transistor making it conducting.

How could I use this circuit to control the Digital input on a microcontroller? Atenciosamente… Washington Souza Gomes. The circuit detects the fluid level by comparing the probe to ground resistance with the internal reference resistor R ref. The internal transistor will be switched ON and Q1 whose base is connected to the collector of the internal transistor will be in OFF condition keeping the relay inactive.

LM Datasheet, PDF – Alldatasheet

External transistor Q1 is l,1830 to the collector of the internal transistor. Some time there may be situations when the fluid resistance probe to ground do not match with the 13K internal reference resistor. Leave a Reply Cancel reply Your email address will not be published. LM based liquid level indicator circuit.

Previous post Next post. In such cases there is option to avoid the internal reference resistor and an external reference resistor of your choice Rx in the circuit can be employed.

Circuits based on this IC requires minimum number of external components and AC signal is passed through the sensing probe datashest in the fluid.