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  1. C

    Two PCBs off of one power source

    Audioguru, The 3.3k ohms can be replaced with 10k ohms? Bruce
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    Two PCBs off of one power source

    Audioguru, I have some headphone cable around the house, but as far as I know, it is not shielded. It is two wire or three wire. These connections are about 5 cm or just over (but not by much), so I'll use regular wire. O.K. on the rest I'll buy the 3.3k (I have the 10's already) resistors and...
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    Two PCBs off of one power source

    Audioguru, You stated" "Of course one or both amplifiers will fry if you connect them to the same speaker and the same battery. Their output DC voltages are completely different and all the battery current will flow between them." What I sated is that I have both runing to a common speaker...
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    Two PCBs off of one power source

    Audioguru, So I put an 8 ohm (can I used 10 ohm?) resistor at the end of the speaker + of the sound effects chip and connect it right to the 0.1 capacitor, which is connected to the 3.3k resistor right?  We don't use the 10k ohm anymore? Here is the best I can do for the FRS schematic in way...
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    Two PCBs off of one power source

    Audioguru, Thanks, but what kind of capacitor, and where does it go? I put an 8 ohm resistor at the end of the speaker +, then a ? capacitor, then a 10k ohm resistor, then into pin 4 of the MC34119. For the FRS,  speaker +, 8 ohm resistor, ? capacitor, 10k ohm resistor, MC34119. Both the...
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    Two PCBs off of one power source

    Audioguru, Sorry for my inability to create a proper schematic, but this is basically a trace of what I have for this toy sound effects chip. The colored boxes (other then black) are for wires which led to switches and LEDs for other sound effects which I will not be using. I clipped those...
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    Two PCBs off of one power source

    Audioguru, I decided to take the time and read through the internet, and once again purchase more components to try what you suggested. What you are saying is that the + outputs of these speaker wires need to be brought down to line level and then fed into an amp to bring the volume back up...
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    Two PCBs off of one power source

    Audioguru, I don't have room for two speakers. I tried to insert a few different values of resistor in the + side of both circuit's speaker lines. I even used a variable resistor pot on each and played with them for some type of result. Neither will share one speaker, no mater what resistor...
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    Two PCBs off of one power source

    I am going to try the two resistors tonight. I found one web page that specified 10k ohms, but did state that this may knock down some of the high end off the sound. If this is no good, then I guess I will try a lower value reistor. As for the low power IC amps. I do not need an amplifier. The...
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    Two PCBs off of one power source

    Are you saying that I need only to put a transistor at the connection of one of the two circuits at the speaker?  I don't need any amplification, and the two circuits only share a common battery and speaker. If so, what should I use as a transistor 10k ohm? Since the FRS already has a volume...
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    Two PCBs off of one power source

    I thought this was a simple question. No-one wants to put in their 2-cents as to what to put in the middle to get two electronic devices to run off of one power supply so they don't fight each other for amperage and/or voltage? Tonight I will attempt the 10 ohm resistor on the FRS posistive to...
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    Two PCBs off of one power source

    Hi, I am trying to run a FRS radio (3 AAA's) and a simple printed on board chip sound effects circuit board (generally 2 AA's, but will work with 3 AAA's it seems without frying it, and it gives me added volume which I needed), off of the same 3 AAA power supply. I was told to use a 10 ohm...
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    project help with toy IC boards

    I've had to take a break from these electronic projects for a bit for a couple of reasons. But, I did go into Radio Shack and buy one of these 741 Op Amps. There is no data on the back of the package, so I have no idea if it is even close to doing what I want. I have not pulled up the internet...
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    slow moving DC motor

    Sure I could use a servo, as long as it is small. But this basic stamp processor is the issue. Can I buy one that is already made up to do what I want? I bet this would require creating some kind of circuit board, inserting a chip and programming it. This would probably be cost prohibitive...
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    slow moving DC motor

    I'm trying to find a micro DC motor that will run at 1 rpm. Basically I need a battery powered analog 60 second stop watch that I can hack open - which I cannot find anywhere. Even a battery powered wrist watch with a sweeping second hand would do, but not one that jumps like the quartz movments...
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    project help with toy IC boards

    I'll try this tonight. Teh gain I assume is adjusted by the resistor you specified, becuse I have no pot of other device to to manually make this adjustment. I also don't need much volume, just a touch. I will create this exactley as you have it here. Bruce
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    project help with toy IC boards

    Here is the schematic I used. The next page of the text states "This first circuit ti the easiest. Just place a 10k resistor between your micro controller and the MC34119. If you want to drive a 8 ohm speaker watch out that you don't pull too much power from your power supply. If you do place 39...
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    project help with toy IC boards

    Audioguru, I have to give you guys credit that you can get any of this stuff to work. I have spent loads of money, buying electronic components, resisters that are of varying values, and having to guess as to what the wattage should be as none of the schematics I have seen either for the LM386...
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    project help with toy IC boards

    What do you think about this UTC KA8602 as an audio amplifier? Bruce
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    project help with toy IC boards

    In reference to the distortion, is there something I can put in place of the pot that would keep the input from what I assume is overdrivng the 386? With this 3.3v splitter, can I still run the 386 off the 9v while also tapping off the 3.3v? Thanks, Bruce
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