Recent content by summersnow

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    Speech Recorder

    Hi. I really don't know why..i read all of the application note and the spec for the chip and i still not able to find out the problem... Audioguru, i read the spec,it shows that 16 ohm is the minimum impedance..but it stated that 8 ohm is acceptable,just that will cause distortion and the...
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    Speech Recorder

    Hi all, I have a problem here. I'm using ISD2548P as a speech IC to record the messages that i need to use for my project.I follow the PUSH BUTTON circuit that provided in the data sheet to record the messages.I try to record and play the speech but nothing can be heard when i play it. :-\...
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    ringing detection circuit

    hi.. actually the D3 is to limits the voltage drop across the LED of the optoisolator to protect it from negative voltages,therefore avoid any possible damage..
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    Far-distance remotely controllable rectifier with back-up battery

    Hi audioguru.. Sorry for the fuzzy JPG file.. Thanks for your advice and i will try my best to learn more about the electronics to finish this project. i'm really a newbie for this.. Really thanks for helping so much
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    ringing detection circuit

    hi audioguru.. thanks for reminding.. actually,i write wrongly in the circuit..i'm using 16V zener diode.. anyway,after i change the resistor to 10kohm,the ringing detector circuit works.. Thanks for your help
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    ringing detection circuit

    Hi all.. I have a problem here. i tried to build a ringing detection circuit. But when i connect the ring and tip of the telephone cable to this circuit,i found out that it automatically being off hook. As a result,it cant be used to detect the ringing signal and it get engaged when i call to...
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    Far-distance remotely controllable rectifier with back-up battery

    hi Thanks for your explanation  :D I understand how the circuit works..but i don't know how to choose the component which can be used for this circuit,such as the resistance of the resistor,the diode and etc.. I havent buy any component or battery to build this circuit. Would you mind...
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    Far-distance remotely controllable rectifier with back-up battery

    Hi all.I found a circuit which basically works like this... A replaceable and rechargeable back-up battery and a ring-controlled switch circuit are provided to the rectifier of this invention to keep the machine working in case of an unexpected failure of the civil power or in response to...
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    ISD2548

    hi, i have a couple of question here.. Q1.may i know how we know the address of the message that we record in the ISD2548 chip? Q2.Can you all please tell me the maximum message which can be recorded into the ISD2548 chip?
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