TRP-3003 DC regulated power supply has constant voltage, constant current and perfect overload protection capability. Since the factory does not provide drawings, the author has mapped out the whole circuit during maintenance and listed common faults and maintenance adjustment methods.
The regulated power supply is constant voltage (CV), constant current (CC), the output voltage is adjustable from 0 to 30V, the output load current is adjustable from 0 to 3A, and the operating characteristic is constant voltage/constant current automatic conversion, which can be loaded with the load. The change continuously changes between the constant voltage and the constant current state, and the intersection between the constant voltage and the constant current mode is called a transition point. It is convenient to charge the rechargeable battery by using the constant current characteristic.
First, the working principle
The whole machine is divided into four blocks: series DC regulated power supply, including adjustable amplification and constant voltage circuit; constant current regulation and constant voltage constant current conversion display part; reference regulated power supply; transformer secondary AC voltage automatic adjustment circuit.
The whole circuit diagram is shown in the drawing.
1. Series DC regulated power supply and constant voltage circuit.
Mainly composed of adjustment tubes T1, T2, T10, T11, op amp IC1 and P1, P2 voltage adjustment potentiometer, reference voltage composed of constant voltage circuit, control T2 base voltage, change the conduction level of the adjustment tube, ensure the voltage regulator circuit Normal work. Here, P1 and P2 are used as coarse adjustment and fine adjustment potentiometer to adjust the voltage. The non-inverting terminal of IC1 is connected with the reference voltage and the adjustment voltage, and compared with the sampling voltage of the inverting terminal to change the current of the adjustment tube.
2. Constant current circuit - also known as current limiting circuit.
That is, when the predetermined current limit is adjusted, the output current remains unchanged, and the output voltage decreases proportionally as the load further increases. The constant current circuit consists of an operational amplifier IC2 and a sampling resistor of 0.15Ω, plus a constant voltage and constant current conversion display circuit. The IC2 non-inverting terminal obtains the reference voltage from the P3 current adjustment potentiometer and the reference power supply regulation W1, and the inverting terminal is connected to the front end of the sampling resistor of 0.15 Ω through the resistance 1kΩ. When the sampling voltage is greater than the reference voltage, the output voltage of IC2 drops, so that the Vb of T2 drops, the output voltage decreases, but the output current remains unchanged, achieving the purpose of current limiting. At constant voltage, T8 turns on and T9 turns off, so the constant voltage (CV) green light is on, and the constant current (CC) red light is off. Because the IC2 output is high at constant voltage, T8 is made through the Zener diode DZ (6V). Turn on, green light is on. When the current limiting protection acts as a protection, the output of IC2 is 0. At this time, Vb of T2 drops to 0 through the diode voltage, and the regulating tube is turned off.
100M 8+2 port passive POE Switch for IP camera
STD-POE5203-10 supports data and power transmission through CAT.5 cables at the same time. And 8+2 port support fast connecting at 100/1000Mbps. It also supports long transmission distance at 250 meters both for power and data, therefore, it saves cost for the project that requiring long distance transmission through extender, fiber and coaxial cable etc. It reduces line losses effectively though 8-core cable supplying power same time. Max power for each port is 30W, which is for IP Camera and POE wirelessaccess point etc.
Features:
REVERSE POE TECHNOLOGY:8 Port 10/100 Reverse POE switch which has latest generation of fast Ethernet reverse POE switching technology. It contains 7*10/100 base T Reverse Poe ports (RPOE),1*10/100 Base date Uplink Port&12V DC out for Powering ONU.
Supports Auto-Negotiation: Each of the ports automatically detect whether connected network devices are running at 10Mbps or 100Mbps and half-duplex or full-duplex mode, and adjusts the speed and mode accordingly ensuring easy and hassle-free operation.
Supports Non-blocking Wire Speed: The switch forwards and receives traffic seamlessly with its Non-blocking wire- speed. Every port of the Switch supports speeds up to 200Mbps in full-duplex mode simultaneously, providing full wire speed to connected devices and allowing you to run a high speed network smoothly.
Cascading support: switches can be cascaded for more users per Building (Up to 1 Main+3 switches )
Port base Isolation u/Hardware VLAN: The feature of Port Isolation is implemented in this unit where in the Ethernet Date of the Uplink Port can be transferred to any of the Downlink ports but the individual Downlink ports cannot communicate with each other.
Over voltage Protection:
Over voltage Protection is provided on each date port to eliminate damage due to connection of higher voltage(Higher than 24V DC. Up to 80V DC). By mistake if user connect more than 24V POE injector then switch will goes on power off mode and will start working again once this high voltage source is removed.
Over current Protection: We have provided over current protection on each port to prevent damage to the switch in case of high current flowing due to any reason. This is provided using Resettable Fuse to facilitate easy maintenance and avoiding frequent change of blown fuse.
Product Application:
7*10/100 Base T Reverse POE Ports(RPOE) & 1*10/100 Base T Uplink Port & 12V DC Power out for Powering ONU
Product Images:
POE Switch,POE Switches Puzzle,POE Switches 4 Port,100M POE Switch
Dongguan Xiaoerduo Electronics Co., Ltd. , https://www.steadysmps.com