Showing posts with label protector. Show all posts
Showing posts with label protector. Show all posts
Thursday, November 20, 2014
Power Amplifier Protector
Now you can protect your HiFi amplifier from damage due to overheating. This circuit will cut off power to the amplifier board at the time the temperature was high. Automatically connect the power when the temperature returns to normal. This circuit uses a sensor NTC Thermister heat and also has a warning sound and reset determination.
Amplifier circuit protector is using popular timer IC NE 555 as the temperature controlled switch. The trigger pin 2 is connected to a potential divider consisting Thermister VR and NTC. Thus the voltage on pin 2 depending on the resilience and determination Thermister VR. NTC (Negative Temperature Coefficient) Thermister has a high resistance in the normal temperature and the resistance decreases as temperature increases. Threshold pin 6 of IC is used to reset the IC if necessary. When the pin 6 voltage gets higher than the IC pin 2 will reset and the output is low.
| Power Amplifier Protector Circuits |
Power to the amplifier board is given by (NC) contact is usually connected from the relay and the switch S2. So that power to the amplifier board will be available through the NC contacts of the relay when the relay S2 and the state is not powered. Thermister resistance is governed by VR triggering pin 2 of IC peaks at normal temperatures. When the temperature inside the cabinet amplifier increases, resistance decreases so that it becomes conductive Thermister. This makes the trigger pin 2 of IC is low and its output is high. T1 works so that the relay energizes and the ringing of a bell. This will damage the electrical supply to the amplifier board. Relay will not be automatically powered when the temperature returns to normal.
Amplifier circuit protectors are very useful to protect your home sound system.
Tuesday, November 18, 2014
Speaker Protector Circuit with DC Protection
Speaker protector function to protect the speakers from damage caused by spikes in the audio signal when first turned on and the DC signal from the audio signal clipping. circuit protectors speakers consist of 2 parts which can protect the speakers are part of the DC signal detection and the delay. Part detetor DC signal composed by 4 pieces arranged diode bridge and a transistor. Then agian delay on the speaker is using a tank circuit protector in the form of capacitors, where the circuit composed of R6, C3, TR2 and TR3. End part of the speaker is using a relay protector. circuit protectors speakers in detail can be seen in the following figure.
Safety Speaker circuit
| Component Speaker Protector Protection |
Thursday, August 14, 2014
Power Supply Monitor Memory Protector Wiring diagram Schematic
This Power Supply Monitor-Memory Protector Circuit Diagram detects low-voltage supply conditions, down to 0.6 V. Dl sets the trip point of the schema. The schema is useful to protect memory diagram from accidental writes in the event of power-supply low-voltage conditions, which cause other diagram to turn off, etc. Response time is about 700 ns. R6 provides some hysteresis to ensure clean transitions.
Power Supply Monitor-Memory Protector Circuit Diagram
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