Homemade chargers for crown 9v circuit. Simple charger for crown batteries
Among the many schemes for assembling chargers for Krona batteries, I found one that was relatively simple and affordable. By the way, the 9-volt battery, known in Russia and the CIS countries as “Krona,” has a 6F22 standard.
The battery consists of 7 4A nickel-metal hydride batteries connected in series. The recommended charging current is no more than 20-30 mA.
The charger is manufactured by redesigning a Chinese-made mobile phone charger.
There are 2 types of inexpensive chargers originating from China. They are pulsed, and both are based on self-oscillator circuits capable of delivering 5 V output.
The first type is the most common. It does not have control of the output voltage, but by selecting a zener diode, which is located in such circuits in the input circuit near the 1N4148 diode, you can obtain the desired voltage. Usually there are two types - 4.7 and 5.1 V.
To charge the Krona you need a voltage of about 10-11 V. This can be achieved by replacing the zener diode with one that has the appropriate voltage. It is also recommended to change the capacitor, which is located at the charging output. As a rule, it is 10 V. You need to install a 16-25 V capacitor with a capacity of 47-220 μF.
The second type of such circuits has control of the output voltage, implemented by installing an optocoupler and a zener diode.
Take a look at the principle of redesigning the second circuit.
It is necessary to remove all components located after the transformer, and leave only the unit that controls the output voltage. This unit consists of an optocoupler, a pair of resistors and a zener diode.
It is necessary to replace the diode rectifier, since manufacturers claim a charging current of 500 mA, and the maximum diode current is no more than 200 mA, although the peak current is about 450 mA. It's dangerous! In general, you need to install the FR107 diode. Thus, charging will produce the required voltage.
The next thing to do is to assemble a current stabilization unit, using the LM317 microcircuit as a basis. In general, you can get by with one quenching resistor instead of assembling a stabilization unit.
But in this example, preference is given to reliable stabilization, because the Krona battery is not the cheapest.
Resistor R1 affects the stabilization current. The calculation program can be downloaded in the Attached files at the end of the article.
The operating principle of this circuit is as follows:
When the Krona is connected, the LED lights up.
A voltage drop is created across resistor R2. Gradually, the current in the circuit decreases, and the voltage that allows the LED to light suddenly becomes insufficient. It simply goes out.
This occurs at the end of the charging process, when the battery voltage becomes equal to the charger voltage. The charging process stops and the current drops to almost zero.
The LM317 chip does not need to be installed on a radiator, unlike , because the charge current is very tiny.
All that remains is to attach the battery connector to the case, which can be made from a non-working battery.
If you use a DC-DC converter, you will get a charger for the Krona via a USB port. like this.
Attached files: .
Soldering the plug to the shielded audio cable Universal protection for batteries
In general, there are a lot of circuits for such chargers. This article presents a simple and affordable option that will help you make a charger for Krona while saving money and effort. The proposed circuit based on charging for a mobile phone allows you to make a device with your own hands. Author of the video blogger Aka Kasyan.
By the way, a 9-volt battery is called Krona only in Russia and other countries that came from the USSR. In the world it is known as standard 6 f 22. Krona owes its name to a simple battery of the same standard, which was produced in the USSR.
You can find everything you need to assemble the device in this Chinese store. Please note products with free shipping.
The battery crown is an assembly of series-connected batteries, a rather rare 4a standard. In general, there are 7 of them. Typically this is a nickel metal hydride type.
Charging schemes for battery Krona
It is recommended to charge the battery crown with a current of no more than 20 - 30 milliamps. It is recommended not to increase the current above 40 milliamps under any circumstances. The charger circuit is relatively simple and is based on a Chinese mobile phone charger. Cheap Chinese chargers come in two main types. Both, as a rule, are pulsed and implemented using self-oscillator circuits. The output provides a voltage of about 5 volts. 
First type of charger
The first variety is the most popular. There is no control of the output voltage, but it can be changed by selecting a zener diode, which, as a rule, in such circuits are located in the input circuit. The zener diode is most often 4.7 - 5.1 volts. To charge the crown we need to have a voltage of about 10 volts. Therefore, we replace the zener diode with another one with the required voltage. It is also recommended to replace the electrolytic capacitor at the charger output. We replace it with 16 - 25 volts. Capacity from 47 to 220 microfarads.
Second type of charging
The second type - the circuit for charging mobile phones is a self-oscillator circuit, but with control of the output voltage through an optocoupler and a zener diode. In such circuits, either a regular zener diode or an adjustable one, like tl431, can be used as a controlling element. In this case, the most common zener diode is 4.7 volts. 
The video shows a modification method based on circuit 2. First we remove everything that is after the transformer, except for the output voltage control unit. This is an optocoupler, a zener diode and two resistors. We also replace the diode rectifier. We replace the existing diode with fr107 (an excellent budget option).
We also replace the output electrolyte with high voltage. We select a 10 volt zener diode. As a result, charging began to output the voltage required for our purposes.
After remaking the charger, we assemble a current stabilization unit based on the lm317 microcircuit. 
In principle, for such insignificant currents you can do without a microcircuit. Instead, install one quenching resistor, but preferably good stabilization. Still, the battery crown is not a cheap type of battery. The stabilization current will depend on the resistance of resistor r1; the calculation program for this microcircuit can be found on the Internet.
This scheme works very simply. The LED will light up when the output is loaded. In this case, Krona, since there is a voltage drop across resistor r2. As the battery charges, the current in the circuit will drop and at one point the voltage drop across each resistor will be insufficient. The LED will simply go out. This will be at the end of the charging process, when the voltage on the Krona is equal to the voltage at the output of the charger. Consequently, further charging process will become impossible. In other words, an almost automatic principle.
You don’t have to worry about Krona, since the current at the end of the charging process is almost zero. There is no point in installing the lm317t microcircuit on a radiator due to the scanty charging current. It won't heat up at all.
At the end, all that remains is to attach a connector for the crown to the output, which can be made from the second non-working crown. And, of course, think about the housing for the device.
Charging for Krona from a dc-dc converter
If you take a small dc-dc converter board, then you can easily make USB charging for the crown. The converter module will increase the voltage of the USB port to the required 10-11 volts. And then along the circuit there is a current stabilizer on lm317 and that’s it.
Instructions
Familiarize yourself with the pinout of the Krona battery. The battery itself or an accumulator of this type, as well as the power supply that replaces it, has a large terminal - negative, and a small terminal - positive. For the charger, as well as for any device powered by the Krona, everything is the other way around: the small terminal is negative, the large terminal is positive.
Make sure that the battery you have is actually a rechargeable battery.
Determine the charging current of the battery. To do this, divide its capacity, expressed in milliamp-hours, by 10. You get the charging current in milliamps. For example, for a battery with a capacity of 125 mAh, the charging current is 12.5 mA.
As a power source for the charger, use any power supply whose output voltage is about 15 V, and the maximum permissible current consumption does not exceed the charging current of the battery.
Check out the pinout of the LM317T stabilizer. If you put it with the front side with the markings facing you, and the terminals down, then there will be an adjustment terminal on the left, an output in the middle, and an input on the right. Install the microcircuit on a heat sink, which is isolated from any other current-carrying parts of the charger, since it is electrically connected to the output of the stabilizer.
The LM317T chip is a voltage stabilizer. To use it for other purposes - as a current stabilizer - connect a load resistor between its output and the control output. Calculate its resistance using Ohm's law, taking into account that the voltage at the output of the stabilizer is 1.25 V. To do this, substitute the charging current, expressed in milliamps, into the following formula:
R=1.25/I
The resistance will be in kilo-ohms. For example, for a charging current of 12.5 mA, the calculation would look like this:
I=12.5 mA=0.0125A
R=1.25/0.0125=100 Ohm
Calculate the power of the resistor in watts by multiplying the voltage drop across it, equal to 1.25 V, by the charging current, also previously converted to amperes. Round the result up to the nearest standard value.
Connect the plus of the power source to the plus of the battery, the minus of the battery to the input of the stabilizer, the adjusting terminal of the stabilizer to the minus of the power source. Between the input and the adjusting terminal of the stabilizer, connect an electrolytic capacitor of 100 μF, 25 V plus to the input. Shunt it with a ceramic one of any capacity.
Turn on the power supply and leave the battery to charge for 15 hours.
Video on the topic
Krona batteries appeared in the Soviet Union, but still remain in demand. This battery is indispensable for devices with high energy consumption, as it produces a much higher current compared to other batteries.
Characteristics of Krona batteries
The batteries are of types AA, AAA, C, D, they are cylindrical in shape and differ only in size. In contrast, the Krona battery has a standard size of PP3 and is a parallelepiped. Salt batteries are characterized by their fragility and cannot be used in high-tech devices. The maximum they are designed for is a watch or other simple device. Batteries are also distinguished by their electrochemical system. Alkaline and lithium batteries have better performance.
Krona mini-batteries are distinguished by fairly high performance; they have an output voltage of around nine (in comparison, a lithium or alkaline AA battery “produces” only 1.5 volts). The Krona battery consists of six one-and-a-half-volt batteries connected in series in one chain (the output is nine volts.) The batteries can have a current of up to 1200 mAh, the standard power is 625 mAh. The capacity of Krona batteries will vary depending on the types of chemical elements. Nickel-cadmium cells have a capacity of 50 mAh, nickel-metal hydride batteries are an order of magnitude more powerful (175-300 mAh). Lithium-ion cells have the highest capacity, their power is 350-700 mAh. The standard size of Krona batteries is 48.5x26.5x17.5 mm. These batteries are used in children's toys and control panels; they can be found in navigators and shockers.
How to charge a Krona battery
In the Soviet Union, carbon-manganese batteries of this size were produced, as well as alkaline ones, which had a higher price and were called “Korundum”. The batteries were produced from rectangular biscuits; for their manufacture, a metal body made of tinned tin, a bottom made of plastic or genitax, and a contact pad were used. Simple disposable Krona batteries allowed a small number of recharges, although this was not recommended by the manufacturer. However, due to the shortage of these nutrients, many books and magazines published
Diagram and description of a homemade automatic charger for charging 9 volt batteries (7D-01 “crown”) and the like.
The charger circuit is shown in Figure 1.
Click on the picture to view.
It consists of a half-wave rectifier on diode VD1, a voltage stabilizer on zener diode VD2 and ballast resistors R1, R2, an electronic switch on transistor VT1 and diode VD3, a threshold device on thyristor VS1.
While the battery connected to the XP2 connector is charging and the voltage on it is below the nominal value, the thyristor is closed. As soon as the voltage on the battery increases to the nominal value, the thyristor opens. The HL1 signal lamp lights up and at the same time the transistor closes. Battery charging stops.
The triggering threshold of the machine depends on the resistance of resistor R4.
Diode D226D can be replaced with any other from the same series, D226B - with another rectifier diode with a rectified current of at least 50 mA and a reverse voltage of at least 300 V, zener diode D813 - with zener diode D814D, transistor KT315B - with another transistor of this series with a current transfer coefficient of at least 50 , thyristor KU103V - thyristor KU103A.
Set up a homemade charger with a connected battery and a DC control voltmeter that measures the battery voltage. As soon as the voltage reaches 9.45 V, the warning light should flash. If this does not happen, then select resistor R4. The device is connected to the network only after the battery is securely connected!!!
Popular charger schemes:
Today, the crown battery is used in many electronic devices. This battery is produced by almost all battery companies. On store shelves you may find Krona batteries from different manufacturers.
In this article you will find out which companies produce this energy source, how to charge it, what the cost of the product is, what it consists of and much more!
What is a crown?
Krona is a rectangular 9 volt battery with two poles at one of its ends. This element was created back in the Soviet Union, but is still popular. May be designated as PP3.
Is the crown a battery or an accumulator?
Initially, this element was produced as a simple battery. But with the development of technology, they began to produce rechargeable batteries of the Krona type. Therefore, there are both battery crowns and conventional ones. At the time of purchase, it is advisable to ask the seller what kind of energy source it is. You can also ask the question: “How many times can you recharge?”
On some of these batteries everything is already written.
The picture shows that it can be charged as many as 1000 times. But the usual crown is only 2 times. After which it may fail. Manufacturers do not recommend charging it.
Battery crown photo
Below are 6 pictures of 9v power supply.
Well, this is exactly what a crown battery looks like.
Why is the battery called crown?
It's difficult to answer this question exactly, but we can assume that it has something to do with her appearance. The crown is commonly referred to as the top of trees or a coin. And from here you can answer what the crown battery is called, or rather where it gets its name from.
The two upper poles can be compared to the upper branches of trees. There is a consonant word for crown. Perhaps this battery takes its name from this word. Because it vaguely resembles this item.
