Thanks for the comments.Hi,
electronics is with voltage and current.
When there are problems with voltage, then give (very important)
* the expected voltage
* and the voltage you measure
also ... voltage often/usually depends on current.
* thus always give the current.
*****
All in all the design des not make much sense to me.
Parts are overcomplicated, like
* U1 ... just to power a LED ..that still includes a series resistor
* RL1 simply could be replaced by transistor
Parts are not well designed, like
* the threshold levels without noise filter and without hysteresis call for trouble.
* Reverse current may flow through the coil of RL3...
Klaus
for debugging it´s urgent to know about the currents. I see no way around this.I can't measure current
LEDs usually are not voltage driven, thus a constant voltage for a LED makes not much sense. In either case a LED needs a current limiting resistor .. and for the LED it makes no difference whether the source is 3.1V or 5V.U1 was originally designed to power both LED's
Maybe "reverse" was not the correct expression. Do a current measurement when ON and when OFF.I don't see which reverse current can flow through RL3.
You talk about power supply.I thought I did enough filtering
I also don't know the manufacturer but in the website I bought it says 3 Watts, 3.0 -3.2 volt, 0.7 amps at the description.What exact vendor and part number is it?
Well, I totally forgot about it, I didn't take diode's resistance depends on its bias into account. But I guess that would give me a dimmer or brighter led with a constant brightness. I will supply constant current to LEDs from now on, thank you. This still doesn't explain why additional load decreases the output voltage of LM317, why doesn't it compensate the error signal?thus a constant voltage for a LED makes not much sense
Well I don't have an oscilloscope but RL1 turns on just fine and only purpose of Q1 is doing that. But there is a fact that Q4 turns on very slowly due to slow increase in gate voltage and it makes the buzzer sound like like it is reborning every time it turns on. It starts with low and painful voice and over time it buzzes normally. I must have somehow made the buzzer voltage like 0 or 24 and nothing in between. The first thing came into my mind is using another relay but come on they are taking a lot of space and I like the slow start characteristic of the buzzer as it warns you for the last time before it buzzes impulsivelyLike input of Q1 for example. I expect either slow edges or oscillation/chattering.
Well true, I ignored that, the biggest reason is not my lack of B12 but it is lack of knowledge. Why is it so important to put filters everywhere? As long as the timer does it's blinking job, and yes it does make the led blink, it is fine. Do I put that filter to lengthen the lifespan of the 555 timer (U3)? There is an output capacitor at the 5V power supply so I think that would act as input voltage filter for the 555timer (U3) anyway.U3 is missing a power supply capacitor.
Believe me it does because of the power supply module which is made by someone else. The circuit is turning of with a delay when I cut the power.And the whole circuit should have a bulk capacitor.
Yes it would be easier but it wouldn't teach me anything and isn't a good idea for mass production (Although I am not planning to make a mass production of this circuit I still want to learn the practices of it.)If I had to do this project, I´d most probably use a microcontroller.
Yes, always good for a surprise and extra work.I also don't know the manufacturer but in the website I bought it says 3 Watts, 3.0 -3.2 volt, 0.7 amps at the description.
Another chance for a bad surprise.the bottom of the perfboard is the ugliest shit you can ever imagine, there are tons of cables running on top of each other
Oh, a new feature ....I like the slow start characteristic of the buzzer as it warns you for the last time before it buzzes impulsively
There are many documents, descriptions, tutorials and videos about this topic. There are many reasons.Why is it so important to put filters everywhere?
Surely not. Good thing is that the NE555 is old and slow. With a modern chip this is a "no-go".There is an output capacitor at the 5V power supply so I think that would act as input voltage filter for the 555timer (U3) anyway.
Very true, bad marketing. The brightness is enough so no problem.BTW: 3.2V and 0.7A isn´t even close to 3W.
I didn't think this circuit is at a level to consider EMI/EMC.EMI/EMC is one reason
Well I know that but as long as it doesn't create any visible drawbacks i don't think about it. As you said maybe it doesn't bother me because I work with low currents, slow components and low frequency switching.Just when a relay turns ON or OFF does not mean this is "clean" switching.
I didn't think this circuit is at a level to consider EMI/EMC.
..
Well I know that but as long as it doesn't create any visible drawbacks i don't think about it.
Wow a brand new IC for me, thank you.
Well that diode was actually to discharge C11 capacitor. The C1 capacitor on the other hand was purposefully discharged slowly through the variable resistor so it didn't need a shortcut to discharge. I will search for clamp diodes next time i use relays.I see a clamp diode for relay turnoff on one relay but not the other.
I would like to learn the regular way of doing things and would prefer to stay away from extra confusion but thanks for this method, I didn't know it existed and it is impressive. I may buy scopes or beg my uncle to use his when I really need itYou can get a scope, PC based
That's very respectful of professionals, they even care about transient of buzzer drivers. By the lack of knowledge I ignored but I started to learn about using parallel capacitors for MOSFETS.The 2N7000 driving a buzzer, you need a scope to look at its drain to see if buzzer
producing any transients.
That made me laugh as the board is disgusting. I will lastly leave pictures here but I am expecting no suggestions to this junkTake a pic of top and bottom of your perf board
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