Indicator for charging a screwdriver 14,4 volts. Encyclopedia of radio electronics and electrical engineering

Encyclopedia of radio electronics and electrical engineering / Chargers, batteries, galvanic cells

 Comments on the article

I bought a cheap Chinese SKIL-2007 screwdriver, a 14,4 V - 1,2A / h battery, in principle, you can work normally, but it turned out to have two drawbacks. First - there is no rotation speed adjustment, I dealt with it quickly, put a switch with a speed controller. Second, there is no indicator for the end of charging. The kit comes with two batteries and a simple charger, made in the form of two separate parts. In a small case, which is plugged into a socket, there is a transformer with a rectifier, it produces 18 V 200 mA at the output, a piece of wire with a connector extends from it. The second part is the charger itself with indicators, here is its diagram - Fig.1.

The green LED indicates that the device is connected to the network. Red indicates the battery is being charged, it will remain lit as long as the battery is connected to the charger. According to the passport, the charge time is 3-5 hours. Since it is impossible to control the end of charging using this charger, I decided to supplement it with my own. Searches on the Internet did not give anything, I came across too abstruse on controllers, the program for which is sent for a fee, or schemes according to which the charge is determined by the brightness of the LED, but this is also not the best option, since during the day in sunlight the brightness seems small, but big in the dark.

I decided to make a simple, reliable, battery charging indicator from available parts. I took a car voltage indicator as a basis (I found it on the shelves in the garage), they are still on sale, it is a cylindrical case that sticks into the car's cigarette lighter, at the end there are three LEDs arranged in a row, red at the edges, green in the middle . Here is his scheme (Fig. 2.) And passport data.

Controlled voltage ranges:

• red LED VD3 - 12 V;
• green LED VD4 - from 12,5 to 14,5 V;
• red LED VD4 - more than 15 V.

Joint glow zones:

• red VD3 and green VD4 - from 12,0 to 12,5 V;
• red VD2 and green VD4 - from 14,5 to 15,0 V.

This circuit without alteration is suitable for a 12-volt screwdriver. It does not contain scarce parts and can be easily assembled by a beginner radio amateur.

In my screwdriver, the voltage of a fully charged battery standing on a charge is 16,5 ... 16,8 V, it will not rise higher, even though it will be charged for a day. Alteration of the car indicator is as follows: the case is disassembled and thrown away, leaving a 16x38 board with three LEDs. Zener diode VD1, replaced by D814G, instead of R2, install a variable resistor of 1 kOhm.

Setting: a power supply with an adjustable voltage of up to 20 V is connected to the input "±" of the indicator. We set the voltage to 16,5 V at the output of the power supply and rotate the variable resistor slider so that only the green LED lights up, as soon as the red VD3 goes out, the rotation is stopped . This completes the setup.

I got the following charging values: Red VD3 - up to 15 V (the battery is discharged). Red VD3 and green VD4 - 15 ... 16,5V (50-80% charged).

Green VD3 - 16,5 - 19,3 (100% charged). Red VD2 - more than 19,3V (this indicator is practically not used).

Then, instead of a variable resistor, set a constant one, in my case it turned out R2 = 470 Ohm, but you can also leave the construction one. the indicator is connected to the standard charger to the "±" battery terminals. Three holes are drilled in the case for the LEDs and the indicator is inserted into the charger case, there is a lot of space there, and they are fixed. Everything native remains in its place.

When the charger is turned on without a battery, VD2 lights up. We insert the discharged battery into the charger, VD2 goes out, the VD3 indicator lights up, as it charges, when the voltage reaches 15 V, the green indicator VD4 starts to glow, and the brightness of VD3 decreases and finally VD3 red goes out, and the green VD4 lights up with full glow, charging can be considered completed.

As a result of this addition to the charger, charging, instead of 3-5 hours according to the passport, ends much earlier. At any time, by the glow of the indicators, you can determine what stage the rechargeable battery is in. According to the tuning method, this circuit is also suitable for other chargers, for a different voltage. To do this, the battery is fully charged, as stated in the instructions for 3-5 hours, then, without removing the battery from the charger, the voltage of a fully charged battery is measured. This voltage is set at the output of an adjustable power supply and by selecting the Zener diode VD1 and resistor R2, the indicator works clearly, as mentioned above.

Author: Kodlozerov S.A.

See other articles Section Chargers, batteries, galvanic cells.

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 Chips based on 14nm technology 2 generations 20.01.2016 Samsung Electronics announced the start of mass production of chips using an optimized 14-nanometer LPP (Low-Power Plus) process. This is the second generation of 14nm FinFET manufacturing technology. Back in the first quarter of 2015, the company announced the launch of production of the Exynos 7 Octa processor based on the innovative 14nm LPE (Low-Power Early) technology. As noted, the use of new technology has ensured high performance and energy efficiency of the new Exynos 8 Octa processor, as well as many other products developed by partners and produced using Samsung FinFET technology. Among them is the Qualcomm Snapdragon 820 processor from Qualcomm Technologies, which will be used in mobile devices in the first half of 2016. By incorporating 14D FinFET into semiconductor devices, significant performance gains can be achieved while power consumption is reduced, Samsung says. The new 15nm LPP process delivers a 14% increase in processing speed and a XNUMX% reduction in power consumption compared to the previous XNUMXnm LPE process through improved transistor structure and process optimization. In addition, the use of fully depleted FinFET transistors provides additional manufacturing advantages and opens up great scalability.

Other interesting news:

▪ Superdiode MAX40203

▪ Mitsubishi DLP projector

▪ TCA9554 Digital Port Expander for I2C Bus

▪ New MOSFETs from 30 to 100 volts in SOT-23 package

▪ Effective sleep training

News feed of science and technology, new electronics

Interesting materials of the Free Technical Library:

▪ section of the site for the radio amateur-designer. Article selection

▪ article Racing car Lotus-56V. Tips for a modeler

▪ article Which war formally lasted more than 2000 years? Detailed answer

▪ article Application of metal coatings when cleaning parts in a tumbling drum. Standard instruction on labor protection

▪ article BLUETOOTH - what is it. Encyclopedia of radio electronics and electrical engineering

▪ article Features of national broadband transformers. Encyclopedia of radio electronics and electrical engineering

Leave your comment on this article:

All languages ​​of this page

Arabic	Hebrew	Polish
Bengali	Hindi	Portuguese
Chinese	Italian	Spanish
English	Japanese	Turkish
French	Korean	Ukrainian
German	Malay	Vietnamese

Home page | Library | Articles | Website map | Site Reviews

www.diagram.com.ua
2000-2024