Let's see how to make LED lighting aquarium yourself. First, let's see why a similar source has been chosen, and then we will show that it is not always reasonable to pay to the store for a lamp specially designed for fish. You will see that LEDs are recognized as the best solution. Let's get started
How the LED lamp
is arranged The composition of a simple flashlight:
- The plastic housing with Camelion inscription provides electrical insulation of the structure.
- Plastic lens holder provides only external protection. The function does not include focusing.
- A cellular structure with parabolic reflectors forms a mirror. The diameter is designed for LEDs of a certain diameter, it is easy to find in the store( shown in the photo).
- Batteries - an integral part of the flashlight. They are two, 1.5 V, connected in series. The result is a 3 volt supply voltage.
- Electronic circuit. We have a current limiter. It consists of a single transistor, a fuse in the collector circuit and a resistor that sets the mode.
flashlight. The principle of operation is shown on the wiring diagram:
- . A three-volt supply voltage is supplied to the transistor collector through a fuse.
- Base mode is set by a 800 Ω resistor.
- LEDs in the amount of 7 pieces are connected in parallel.
- Transistor switch is triggered when the voltage is exceeded. Then, through the 800 ohm resistor, the base opens slightly, reducing the resistance of the pn-junction collector-emitter.
- The transistor current increases, shorting the excess and taking off the load.
- With a relatively large voltage overshoot of its nominal value, the transistor goes completely into the open state, the current rises sharply, the fuse burns out at a specific moment.
A person who supplies batteries of different ratings does not risk. As a result, the fuse will simply burn out. So, before performing LED lighting, you need to think about the power source. According to PUE and other documents( GOST 50571.11) it is forbidden to use equipment with a voltage higher than 50 V AC closer than 60 cm from water sources. We believe the aquarium is included in the definition. Manufacturers produce equipment, but more often it works from the adapter. Otherwise, the fish are at risk.
From the installation, it is clear that the body has become a circuit minus. The board is transmitted through a metal contact that runs inside( along the batteries) and touches the ring that runs along the perimeter( see photo).The output uses low supply voltage. It is not necessary to use 3 V. Discuss the clarification.
Power Supply for LED Aquarium Lighting
We recommend using adapters for 12 or 5 V for the purpose of powering LED aquarium lighting. These ratings are easier to obtain. In this case, the cord is usually either of arbitrary length, or the required 0.6 meters. Acceptable use:
- Power adapters for laptops, printers, other office equipment.
- Chargers for cell phones, iPads, etc.
- Power supplies for external modems, routers.
- It is possible to design your own source of the desired voltage.
In addition to these options, there is an additional set. For example, try to regularly use the tires of the power supply unit of a personal computer. There are different branches there: 5 V, and +12, and -12, 3.3 V. Any portable radio detects a charger, and adapters break less frequently than products. We advise you to look for people selling the required, and at a relatively low price.
For the manufacture of its own source, special converter microchips are sold. And the conversion goes in any direction. Most of the AC is formed constant. The impulse power supply units actually contain a microcircuit( inverter) inside, which cuts the rectified voltage( amplitude up to 700 V) by pulses, which then go through the transformer and are smoothed to the desired level. This ensures galvanic isolation by current, the necessary power is generated.
Power supply unit onvoltage converter chips
This is not required, we will manage with much simpler means. Suppose our scheme is taken( even two) from the official manual on the application of SR036 and SR037 microcircuits. The difference between them in the output stabilized( regulated) voltage. In the first case - 3.3 V, in the second 5 V. According to the inherent features, the chips are intended for computer power supplies. For example, the maximum value at the input is 700 V. This is a typical value obtained on electrolytic( polar) capacitors after the rectifier( diode bridge).
We briefly explain the essence of what is happening on the screen. In the first case, a power source is shown for obtaining DC voltages of 5 or 3.3 V, depending on the chip used, approximately 18 V not stabilized( with a high level of harmonics).This is realized by simple inclusion according to the recommendation. It is not necessary to know the concept of MOSFET( MOS) transistor. The main thing is that it is called VN2460N8.On specialized sites it is easy to find an analogue for him or order in the store.
Transistor is quite expensive, within 50 rubles. Required for work. Let's see how the chip for voltage conversion! Typical schemes have already led, but what lies inside? With the kind permission of the manufacturer, they took a voltage diagram and the internal circuit design of the SR036( SR037) chip:
At the input there is a comparator, and the input voltage, consisting of bell-shaped pulses, is fed to the inverse input. When the level exceeds a certain threshold value, a logical unit will appear at the output, locking the transistor VN2460N8.Before locking the key is open, a 220 microfarad capacitor is charged through it. The level of voltage pulsations of +18 V strongly depends on this. The comparator takes the reference voltage in the form of circuit earth, that is, zero. Its threshold is in the region of 20 V. When the bell exceeds the specified value, the transistor is locked, and the capacitor begins to discharge through the stabilizer( REGulator).
- Zener diode.
Stabilitron is two-channel and works in both directions. Do not forget that the potential of the substrate constantly fluctuates around +18 V, and you need to apply a positive potential to the gate. This suggests that the logic level of the comparator unit is provided in the region of 22 V( judging by the current-voltage characteristic of the transistor).Only then is the n-type channel induced. For the latter, there is a double-sided zener diode. It is not written what voltage limits, we believe, in the region of 3.3 or 5 V, depending on the type of chip. As a result, it is acceptable to use a comparator from conventional logic( TTL, etc.) with standard voltage levels. The zener diode limits the voltage drop caused between the source and the gate by the presence of a 220 microfarad capacitor. As a result, the comparator should only slightly exceed the specified value in order for the voltage drop to change direction, opening the transistor switch.
- Stabilizer( REG)
Gives out a voltage of +5 V. The stabilizer is constantly fed from a 220 microfarad capacitor, due to which on the graph V unreg constantly shows a negative slope. From here, the main stabilized voltage is fed( +5 or +3.3 V).
The transistor and the capacitor are considered an integral part of the circuit. After the diode bridge, the voltage is expected to be bell-shaped. You can not straighten to the end. Otherwise, the conditions of the comparator are violated. We are confident that the LED spotlight, working from such a power supply, will work perfectly - stability is guaranteed. Then they decide to apply power +5 or +3.3 V. The cost of the microcircuit is 4.5 dollars.
We explain the reason for the actions described. It is not always possible to make LED lights for an aquarium out of available tools. For example, USB lamp when powered by an adapter easily fails. The charger has a slightly higher rating. So, you need to be tied tightly to the power used. Even for a personal computer, relatively large tolerances are left that can lead to system malfunction. In our case, there is guaranteed a certain nominal value, and the load current is determined by the formula:
P = Uin x Uin / 200 kΩ +( 16 V - Uout) x Iout.
We explain how to use the formula. Under Uin means the effective value of the rectified voltage, and Iout - load current. P is the dissipated power. For MSOP-8 enclosures it is 300 mW and 1.5 W for execution in the SO-8 slug( see figure).As a result, the performance depends not only on the size of the chip, but also on the mains supply voltage( the diagram shows that both 220 and 120 V. The solution is universal for all countries and standards).It is permissible to put a thermal relay( take from any device or buy).In our case, the temperature does not exceed +150 degrees. A protective relay( typical at 135 degrees Celsius) from most transformers( even from home theaters and video players) will do.
LED Aquarium Lighting Design
It's easier to equip aquarium lighting with LED tape. It is enough to put it on the reverse side. Fits a lot of adhesives. Please note that individual LED strips are afraid of water, be able to read the label( see previous reviews).In short, the IP class is required higher. In a bad scenario, however, only the tape will suffer, the voltage of its food is not capable of causing harm to a healthy person.
LED lighting for a plant aquarium is required for the formation of chlorophyll. However, the frequency is chosen closer to the daylight. Someone seems to need a better lighting of the aquarium with LED lamps placed in the water column, but it is more rational to surround the glass around the perimeter. The frequency of daylight is not so absorbed by the glass to invent special designs. The advantage of concentrating energy in the required area: 430 nm for chlorophyll A and 470 nm for chlorophyll B.
The corresponding LEDs are easy to find on sale. And what will be required, it is easy to find out by reading the literature on the subject of algae placed in the aquarium. It turns out to efficiently feed its vegetation. And even the calculation of LED lighting for the aquarium is not needed!