Overload indicator and voltage stabilizer protection. Encyclopedia of radio electronics and electrical engineering
Encyclopedia of radio electronics and electrical engineering / Power Supplies
Comments on the article
To monitor the operation of any voltage stabilizer, an indicator LED with a load resistor is usually installed at its output. In the event of a short circuit, the LED will turn off, but then the stabilizer may fail. To protect it, a standardized fuse is usually installed at the output of the device.
Unfortunately, the latter have discrete protection ratings: 0.1A, 0.15A, 0.25A, 0.5A, 1.0A, 2.0A, 3.0A, etc. But what if you want to index the load, for example, in 0.2A?
In this case, you can assemble the circuit shown in Fig. 1, where, by selecting the resistor R1, the load necessary for this stabilizer is set.
The scheme of Fig. 1 can be used not only for the stabilizer on KREN5A, but also for any other. In our case, the circuit is "controlled" by the parameter of the field-effect transistor Uots.
The circuit can use field-effect transistors with a low cutoff voltage and a p-channel: KP103E, 2P103A, KP201E, KP103Zh, KP103I. By selecting the value of the resistor R1 in the range of 0,1 ... 0,5 Ohm, you can set the required load, at which the LED will turn off.
If it is necessary that the LED lights up during overload, you can use another circuit (Fig. 2), where instead of the optocoupler LED, you can install any LED, excluding optocoupler U1 and relay K1 from the circuit.
The circuit of Fig. 2 in the "full" version is also designed to protect the voltage stabilizer from overload. It is assembled on a relay K1 controlled by an optocoupler U1. The stabilizer overload current is selected using the resistor R1. In the event of an overload, relay K1 disconnects the load with its contact K1.1, and self-blocking with contact K1.2 until the overload is eliminated. To start the circuit (Fig. 2), briefly press SA1.
To indicate overload and protect the negative polarity stabilizer, it is necessary to install a transistor VT1 with an n-channel and a low cutoff voltage instead of a field-effect transistor with a p-channel. In this case, VT2 must have a different conductivity, and the polarity of the connection of the LEDs and the power supply must be reversed.
Overload indicator circuits for other types of field-effect transistors can be found in [1, 2].
Details. Relay K1 type RES-22 (passport RF4.500.129) or any other with a response voltage of 7 ... 11 V, for example RES-6. Optocoupler U1 type 3OT110G, AOT110G or AOT127. Resistor R1 is a home-made wire resistor or type C5-16V with a resistance of 0,1 ... 0,5 Ohm. Microswitch SA1 type MP9, MP10.
References:
- Karapetyants K. Stabilizer overload indicator//Radio. - 1983. - No. 2. - P.31.
- Rovkov B. Stabilizer overload indicator//Radio. - 1989. - No. 12. - P.80.
- Nikitenko O. Voltage regulator with indicator//Electrician. - 2002. - No. 4. - C.2.
Authors: V.G. Nikitenko, O.V. Nikitenko
See other articles Section Power Supplies.
Read and write useful comments on this article.
<< Back
Latest news of science and technology, new electronics:
Artificial leather for touch emulation
15.04.2024
In a modern technology world where distance is becoming increasingly commonplace, maintaining connection and a sense of closeness is important. Recent developments in artificial skin by German scientists from Saarland University represent a new era in virtual interactions. German researchers from Saarland University have developed ultra-thin films that can transmit the sensation of touch over a distance. This cutting-edge technology provides new opportunities for virtual communication, especially for those who find themselves far from their loved ones. The ultra-thin films developed by the researchers, just 50 micrometers thick, can be integrated into textiles and worn like a second skin. These films act as sensors that recognize tactile signals from mom or dad, and as actuators that transmit these movements to the baby. Parents' touch to the fabric activates sensors that react to pressure and deform the ultra-thin film. This ... >>
Petgugu Global cat litter
15.04.2024
Taking care of pets can often be a challenge, especially when it comes to keeping your home clean. A new interesting solution from the Petgugu Global startup has been presented, which will make life easier for cat owners and help them keep their home perfectly clean and tidy. Startup Petgugu Global has unveiled a unique cat toilet that can automatically flush feces, keeping your home clean and fresh. This innovative device is equipped with various smart sensors that monitor your pet's toilet activity and activate to automatically clean after use. The device connects to the sewer system and ensures efficient waste removal without the need for intervention from the owner. Additionally, the toilet has a large flushable storage capacity, making it ideal for multi-cat households. The Petgugu cat litter bowl is designed for use with water-soluble litters and offers a range of additional ... >>
The attractiveness of caring men
14.04.2024
The stereotype that women prefer "bad boys" has long been widespread. However, recent research conducted by British scientists from Monash University offers a new perspective on this issue. They looked at how women responded to men's emotional responsibility and willingness to help others. The study's findings could change our understanding of what makes men attractive to women. A study conducted by scientists from Monash University leads to new findings about men's attractiveness to women. In the experiment, women were shown photographs of men with brief stories about their behavior in various situations, including their reaction to an encounter with a homeless person. Some of the men ignored the homeless man, while others helped him, such as buying him food. A study found that men who showed empathy and kindness were more attractive to women compared to men who showed empathy and kindness. ... >>
| Random news from the Archive Diabetes is determined by tears
07.09.2012
In most cases, diabetes is diagnosed using sensors that measure blood glucose levels. But now scientists have created a new type of biological sensor capable of detecting minute concentrations of glucose in human tears, saliva and urine as well.
The innovative invention promises to significantly reduce the cost of diagnosing diabetes, since its manufacturing technology is low-cost and uncomplicated. This method will also be convenient for patients, since they do not have to constantly donate blood. The developers promise that with the introduction of this method, the number of injections will be significantly reduced or completely eliminated. "It's essentially a non-invasive way to measure glucose in the body," said one of the project leaders, Jonathan Klassen, a former Purdue University graduate student and now a researcher at the US Naval Research Laboratory.
The sensor that detects glucose levels consists of three main parts: nanosheets that resemble microscopic rose petals and are made of graphene, platinum nanoparticles, and the enzyme glucose oxidase. Each 'petal' is made up of multiple layers of graphene. Its edges have incomplete chemical bonds, that is, defects to which platinum nanoparticles can attach. Their connection with nanoplates forms electrodes. The glucose oxidase enzyme then attaches to the platinum nanoparticles. This enzyme converts glucose into hydrogen peroxide, which in turn sends a signal to the electrode.
The sensor is able to detect glucose at concentrations as low as 0,3 micromoles. Thus, it is much more sensitive than other biosensors based on graphene, nanocarbon tubes, graphite, and metal nanoparticles.
So far, the invention is used to diagnose diabetes, but the same technology can be successfully applied in other areas of medicine. It is enough to change one enzyme for another, and you can use this method in tests for Parkinson's and Alzheimer's disease. It can even be used to control the degree of alcohol concentration in exhaled air. The method is economical and fast, and the test equipment is simple and portable.
|
Other interesting news:
▪ Barracuda XT High Capacity Hard Drives
▪ Notebook Toshiba Libretto W100
▪ Pregnancy changes the mother's bones
▪ 4 Gb LPDDR8 DRAM Mobile Memory Chips
▪ Fabric with built-in heating
News feed of science and technology, new electronics
Interesting materials of the Free Technical Library:
▪ site section Electric motors. Article selection
▪ article The third is not given. Popular expression
▪ article What determines the sex of the embryo in reptiles? Detailed answer
▪ article Hazelnut. Legends, cultivation, methods of application
▪ article Computer devices. Directory
▪ article Power supply for the ionizer. Encyclopedia of radio electronics and electrical engineering
Leave your comment on this article:
All languages of this page
Home page | Library | Articles | Website map | Site Reviews
www.diagram.com.ua
2000-2024
Arabic
Bengali
Chinese
English
French
German
Hebrew
Hindi
Italian
Japanese
Korean
Malay
Polish
Portuguese
Spanish
Turkish
Ukrainian
Vietnamese