Its just that i got a problem bout a simple electronic circuit and dont know what should be done to rectifi it, i've given an explanation of it at www.geocities.com/ebcalc/ics/2way.htm
Any help will be appriciated.
[tt]This is a problem of designing a two way switch related with electronics[/tt]
The electronic problem
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beyondsociety
Re:The electronic problem
Link to page not found.www.geocities.com/ebcalc/2way.htm
Any help will be appriciated.
Re:The electronic problem
Switching the switches off doesn't draw the output down to any level but leaves it tristated. In a way, it makes the output of the switch unreliable. Making the output of your xor unreliable, making the state of your LED unreliable unless both switches are ON, after which the LED will predictably be off.rich_m wrote: Its just that i got a problem bout a simple electronic circuit and dont know what should be done to rectifi it, i've given an explanation of it at www.geocities.com/ebcalc/ics/2way.htm
Any help will be appriciated.
Try attaching a resistor between the output of each switch and the ground, that should help it.
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rich_m
Re:The electronic problem
thanks, it works fine now. i have a diagram of the new 'rectified' circuit here at www.geocities.com/ebcalc/ics/rec.htm
can anyone tell me the purpose of using the
1)transistor
2)47uf
3)& those resistors
can anyone tell me the purpose of using the
1)transistor
2)47uf
3)& those resistors
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Curufir
Re:The electronic problem
Well it has been many moons since I did electronics, but I'll give it a shot. Basically everything from the capacitors to the transistor is there to stop excessive current flowing through the logic gates (Which will keel over and die). The cap and resistors are there for spikes when you hit the switch (Effectively giving you an CR circuit to dampen things), the transistor to stop you passing current directly through the gate.
I'm sure the other guys will correct that if my memory is playing tricks on me.
I'm sure the other guys will correct that if my memory is playing tricks on me.
Re:The electronic problem
The capacitor levels the power level to a steady current (which obviously only works on DC).
The 690ohms resistor lowers the current output by the transistor to a nice value for the LED, so it doesn't go boom instantly. They don't like high tensions.
The 2 10k resistors bring the output of the switch back to 0 once you switch it off, and them being 10k means you don't instantly unload the battery.
The transistor + the 47kohms resistor function as an amplifier.
Things I think are superfluous:
The transistor with 47k resistor. If the XOR circuit would be analog logic it'd be used to make the output a strict 5v/0v level, but since the XOR is digital, and it's an active component, there's no reason why it would need to be amplified. It might serve not to overload the CMOS chip though, although they should be able to support one LED.
The capacitor. Why in gods name level something from a static source? It's pretty much as level as you can get it, and it mainly means higher power consumption each time you connect it to the battery -> higher battery drain. Don't see any use for it. It'll still work without it.
Hope this clears it up for you.
[edit]
I missed that one point where the LED is now inverted in connection order. It shouldn't matter any bit, the inversion. It just uses the transistor the other way around. AFAIK, the BC547b is a PNP transistor, which means it must be switched this way.
If you'd use a BC547a (NPN afaik again), you should be able to connect the power to the collector, the signal from the cmos to the base and the output to the LED (plus side), and then the minus of the LED to the resistor, resistor to ground. Should also work and pretty much function the same.
[/edit]
The 690ohms resistor lowers the current output by the transistor to a nice value for the LED, so it doesn't go boom instantly. They don't like high tensions.
The 2 10k resistors bring the output of the switch back to 0 once you switch it off, and them being 10k means you don't instantly unload the battery.
The transistor + the 47kohms resistor function as an amplifier.
Things I think are superfluous:
The transistor with 47k resistor. If the XOR circuit would be analog logic it'd be used to make the output a strict 5v/0v level, but since the XOR is digital, and it's an active component, there's no reason why it would need to be amplified. It might serve not to overload the CMOS chip though, although they should be able to support one LED.
The capacitor. Why in gods name level something from a static source? It's pretty much as level as you can get it, and it mainly means higher power consumption each time you connect it to the battery -> higher battery drain. Don't see any use for it. It'll still work without it.
Hope this clears it up for you.
[edit]
I missed that one point where the LED is now inverted in connection order. It shouldn't matter any bit, the inversion. It just uses the transistor the other way around. AFAIK, the BC547b is a PNP transistor, which means it must be switched this way.
If you'd use a BC547a (NPN afaik again), you should be able to connect the power to the collector, the signal from the cmos to the base and the output to the LED (plus side), and then the minus of the LED to the resistor, resistor to ground. Should also work and pretty much function the same.
[/edit]
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rich_m
Re:The electronic problem
thanks that info was real useful, btw i've found a way (or think i've found a way) to make a two way switch without using electronics, & so i'm doing a four way switch. i'll post a detailed report sometime later. 
Re:The electronic problem
easy solution: take a 2.2V power supply and use two-way switches that give output one or two. Then connect the power to one side, the ground to the other, the output to the XOR and that output to the LED.
Other idea which only works with 2 is to do this and connect a standard 4-diode network to the output. Then connect the LED to that. Using a normal light you don't need the diode stuff.
Anyway, keep us informed been a while since I've done any electronics, but I should start again in february somewhere, something called "realtime and embedded systems"...
Other idea which only works with 2 is to do this and connect a standard 4-diode network to the output. Then connect the LED to that. Using a normal light you don't need the diode stuff.
Anyway, keep us informed
been a while since I've done any electronics, but I should start again in february somewhere, something called "realtime and embedded systems"...