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I need help with my very simple relay circuit

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kafor1:
So i made a simple controller/light indicator so my problem is my relay buzzes
Components used
555 timer
6v relay
10k ohm
6.3v flashlight bulb idk the input current
9v battery
470 ohm
Pushbuttons
3v led
41 ohm

Problem
My relay buzzes after connecting the 6.3v bulb to the NO contact relay (assuming the relay is already energized)
Well it buzzes after energizing the relay
Things tried:
I tried connecting my 6.3v directly to 9v battery and it glows but light is slowly fading
I tried using many resistors lowest value is 41 ohm and highest is 10k ohm it doesnt glow at all
Tried directly connecting battery to relay, still buzzes
Checked if the relay is broken, its not ,because after tryint it with a regular led the relay triggers, and it only buzzes the moment i connected.the 6.3v to the NO(+) and the (-) to the ground.

Plz help me i really want to make this

vk6zgo:

--- Quote from: kafor1 on November 28, 2018, 06:54:22 am ---So i made a simple controller/light indicator so my problem is my relay buzzes
Components used
555 timer
6v relay
10k ohm
6.3v flashlight bulb idk the input current
9v battery
470 ohm
Pushbuttons
3v led
41 ohm

Problem
My relay buzzes after connecting the 6.3v bulb to the NO contact relay (assuming the relay is already energized)
Well it buzzes after energizing the relay
Things tried:
I tried connecting my 6.3v directly to 9v battery and it glows but light is slowly fading.

--- End quote ---
Think about this---- is that telling you something?
A 6.3v flashlight bulb is normally used with a lantern battery, what is different about your 9v battery?

--- Quote ---I tried using many resistors lowest value is 41 ohm and highest is 10k ohm it doesnt glow at all
Tried directly connecting battery to relay, still buzzes
Checked if the relay is broken, its not ,because after tryint it with a regular led the relay triggers, and it only buzzes the moment i connected.the 6.3v to the NO(+) and the (-) to the ground.p

Plz help me i really want to make this

--- End quote ---

Your schematic is really hard to decipher------- what exactly are you trying to achieve?

Nerull:
9v batteries are hot garbage when it comes to internal resistance, your lamp is likely drawing enough current to significantly affect the voltage supplied to your circuit. You have zero bypass caps for power or pin 5 of the 555, so it's likely oscillating due to the messy supply voltage.

I'm pretty sure this is the OPs circuit, it's should be working in bistable mode:



It does function in the simulation world, at least.

spec:

--- Quote from: Nerull on November 28, 2018, 07:32:39 am ---9v batteries are hot garbage when it comes to internal resistance, your lamp is likely drawing enough current to significantly affect the voltage supplied to your circuit. You have zero bypass caps for power or pin 5 of the 555, so it's likely oscillating due to the messy supply voltage.

--- End quote ---

Yeah, I am not a fan of 9V batteries either. Be nice if you could get LiIon versions. Not only is the basic structure difficult with 7 small cells connected in series, but the performance varies radically from manufacturer to manufacturer.

IIRC the output resistance of a PP3 is around 60R which makes them unsuitable for supplying high currents. One dodge to improve the performance of a PP3 is to put a 1mF or lager capacitor across the terminals.

Incandescent bulbs, if that is what is being used, are a nasty loads. Their filament resistance has a high positive temperature/resistance coefficient,  so much so that their initial resistance can be around 10% of their hot operating resistance. This means that they take a huge gulp of current when first connected to a voltage source.

vk6zgo:
OK, I think I can see what you are doing.
The (unnamed) pin of the 555 goes low (In other words, goes close to zero volts, assuming the negative terminal of the 9v battery to be the zero reference)

This, in turn, operates the relay, via the 41 ohm resistor, closing the NO contacts, & connecting the 6.3v globe across the same battery which powers the 555 and the relay.

Looking back to my earlier answer, what did you conclude about the globe's glow "fading"when you connected it directly across the 9v battery?

Two things to think about:-
Try operating the globe from a totally separate battery.

Do you really need the 41 ohm resistor?
Seriously think about whether operating the relay directly from the 555s pin is really the best way to do things.

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