Basic microphone element to a speaker - Electronic Circuits Projects Diagrams Free

jbelectric777 · 27th May 2008, 11:20 PM

Hi All, I was wondering if I could use an NE555 timer along with a transistor to drive a 4 ohm speaker. I dont know much at all in that area, maybe I dont even need a 555 and it can be done with a few transistors and caps. If possible provide a link or draw and post something for me. All I wanna do is drive the speaker via the mic element. Thanks in advance for any help

audioguru · 27th May 2008, 11:53 PM

The max allowed output current from a 555 is only 200mA. If the 555 has a 10V supply then its max current into a 4 ohm speaker will try to be 525mA or 1.9A depending on how the speaker is connected. The 555 will blow up.

A 555 is a timer and an oscillator, not an amplifier.

Your mic needs a preamp that is designed for its type and the speaker needs a power amplifier.

Hero999 · 28th May 2008, 05:44 PM

Use a 64

hm: speaker if you can get hold of one - it'll be much louder than an 8

hm: with a restor in series with it.

jbelectric777 · 29th May 2008, 01:09 AM

ok, i understand the 555 is only good for 200ma and it did get real hot so what should i use a transistor ? what kind?

audioguru · 29th May 2008, 01:16 AM

A 555 is not a power amplfier. A mic feeds a preamp which amplifies its low level about 30 times, then it feeds a volume control that feeds a power amplifier. The power amplifier drives the speaker.

A 555 makes clicks, buzzes or high frequency whines and its output can be switched ibto the input of the power amplifier.

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27th May 2008, 11:20 PM	(permalink)
jbelectric777	Basic microphone element to a speaker Hi All, I was wondering if I could use an NE555 timer along with a transistor to drive a 4 ohm speaker. I dont know much at all in that area, maybe I dont even need a 555 and it can be done with a few transistors and caps. If possible provide a link or draw and post something for me. All I wanna do is drive the speaker via the mic element. Thanks in advance for any help __________________ "Yesterday is History, Tomorrow's a Mystery"

27th May 2008, 11:53 PM	(permalink)
audioguru	The max allowed output current from a 555 is only 200mA. If the 555 has a 10V supply then its max current into a 4 ohm speaker will try to be 525mA or 1.9A depending on how the speaker is connected. The 555 will blow up. A 555 is a timer and an oscillator, not an amplifier. Your mic needs a preamp that is designed for its type and the speaker needs a power amplifier. __________________ Uncle $crooge

28th May 2008, 05:44 PM	(permalink)
Hero999	Use a 64hm: speaker if you can get hold of one - it'll be much louder than an 8hm: with a restor in series with it. __________________ I also post at the following sites: http://www.stop-microsoft.org http://www.heated-debates.com Screen name: Aloone_Jonez

29th May 2008, 01:09 AM	(permalink)
jbelectric777	ok, i understand the 555 is only good for 200ma and it did get real hot so what should i use a transistor ? what kind? __________________ "Yesterday is History, Tomorrow's a Mystery"

29th May 2008, 01:16 AM	(permalink)
audioguru	A 555 is not a power amplfier. A mic feeds a preamp which amplifies its low level about 30 times, then it feeds a volume control that feeds a power amplifier. The power amplifier drives the speaker. A 555 makes clicks, buzzes or high frequency whines and its output can be switched ibto the input of the power amplifier. __________________ Uncle $crooge