series voltage regulator chip has a minimum pressure difference of 2V, so 7V power supply is the best choice for the 7805. Its upper input voltage should be 35V. Attached is the DataSheet of TI's LM7805.
Maximum input voltage of different models of three-terminal regulator blocksDifferent, the 78 series can be adjusted between 2V and 37V. 78 series three-terminal regulator block, the output voltage is a fixed positive voltage regulator block.
lm7812 is a three-terminal voltage regulator IC chip component, suitable for all kinds of power supply voltage regulator circuits, good output stability, easy to use, output overcurrent, overheat automatic protection.
The minimum voltage drop of the single-tube voltage regulator circuit is 0.7V. Since the on-voltage of the commonly used silicon tube is about 0.7V, the minimum voltage drop of the single-tube voltage regulator circuit should be greater than or equal to 0.7V in normal operation to ensure that the tube is onAs a load, the output voltage should be 5V.
2. First, the output load has a short-circuit fault. Two, the chip has a problem. The TV is in standby state, so it can not turn on the machine, for example, the user mistakenly presses the "standby" button of the TV remote control, so that the TV is in standby state, at this time, you can press the "standby" button of the remote control again to wake up the TV and restore normal.
3, after the TV is turned on, it is found that the backlight is not bright, and it may be that the TV power board is broken. ON the end of 6V without 24V indicates that the power board is broken, as for the motherboard is another discussion.
1, although using a voltage regulator chip to power Bluetooth is the right choice, but I feel that the voltage regulator diode is very Geek, so I designed the following circuit to power the Bluetooth module, where VCC5v, D1 is a voltage regulator diode, R3 is a current limiting resistor, in the case of sufficient current, can maintain 3v voltage.
2, V down to 3V, with a LM1117-3 chip is not solved, do not need to change the charger circuit.
3, output electricityThe voltage is 5V, and the output current can reach 5A. You use it to connect a 5V power supply, as long as the USB port is connected correctly, you can fully charge your phone. However, the 7805 is a linear power supply, and the heat may be large when working, and a heat sink is required.
4, FM1702SL is a universal card reader chip, it can not work stably at 3V power supply voltage, need external power supply stable at 3V, you can use like AMC1117-3 or AX1007-3 low voltage difference three-terminal regulator.
5, the main power supply used in various on-board chips on the motherboard is5V and 3V, while 12V is mainly used for PCI-E, PCI slot and fan interface, in which PCI-E slot in addition to 12V will use 3V power supply, PCI slot needs to use 12V, -12V and 5V.
A voltage regulator chip is an electronic component that can stably adjust the input voltage to a specific output voltage. Its working principle is: when the input voltage changes, the voltage is stabilizedThe chip detects this change and adjusts the output voltage to keep it at a specific voltage level.
Voltage regulator is a power supply circuit or power supply equipment that can automatically adjust the output voltage, and its role is to stabilize the power supply voltage required by large fluctuations and non-compatible electrical equipment within its set value range, so that various circuits or electrical equipment can work normally under the rated operating voltage.
Three-terminal voltage regulator A three-terminal voltage regulator is an electronic device that controls the output voltage by comparing the input voltage with the reference voltage. It usually consists of three parts: the input side and the comparison electricityRoutes and outputs.
LCM, interface converter, instrument, flashing light, product control circuit with clock display. Voltage regulator ics include: DC/DC boost chip 5V, 3V, 3V, boost IC output voltage adjustable, LDO regulator 6206 series, LDO series with enable end, low voltage detection reset IC, backlight driver chip, LED driver IC, MOS tube and so on.
LM337 is a three-terminal tunable output linear regulator integrationThe circuit. The output voltage range of the LM117 is 2V to 37V, and the load current is up to 5A. The LM117 can be used in many special ways.
TB1238AN21 is an integrated circuit control chip with 56 pins. Each function and voltage of the chip's pins can detect and repair chip faults.
If there is an exception, the chip may be damaged. Check pin function: Check whether the pin function of the voltage regulator chip is the same as the normal value. You can consult the relevant technical information or refer to other normal use of the chip for comparison.
There is anotherIt may be that there are other components on the circuit board that output 5V voltage to the power cord connected to the output pin of the LM1117-3, and the LM1117 has no pull-down function. If all the above reasons are excluded, the LM1117 is still abnormal.
The 8 pin description pins (COMP) of the power management chip are error amplifier compensation pins. The RC compensation network should be connected between the pin and the inverting input of the error amplifier (VFB) to improve the performance of the error amplifier. The foot (VFB) is the inverting input of the error amplifier.
sb1733 Voltage regulator 3Cascade rated voltage 20V, rated current 2A. Triple tube power 10W, frequency 100MHz. The temperature coefficient of the three-tube is 0.5, and the forward pressure drop is 4V.