How do I combine these circuits?

Thread Starter

Swaysceptile

Joined Oct 28, 2021
16
We have a project coming up in my Engineering Drafting and Design class and I don't have much idea yet on how to accomplish it. We are tasked to combine different circuits to design one complete device. Then we need to of course make the Schematic (and simulate it), as well as creating the PCB. I have no problems with using the software to accomplish them. I just don't know how to do the actual design... As we only did this class for 6 weeks so I don't have proper understanding of circuits and have to rely on YT tutorials.

My idea is to combine a Battery Monitoring circuit , Water Level Indicator circuit, and a Police Siren Circuit all together to form a one complete functional system that has multiple features.

Attached are the individual circuits (I found them on several websites):

As you can see, they are three different circuits. I need to combine them into one. It's no problem to go look for circuits on the internet as the main objective of my class is to improve software skills. However, how can I combine the three of them? Of course I have to modify the components but that's all I know. Not sure how to make it work.


Source/s:

Battery Monitoring Circuit:
https://circuitdigest.com/electronic-circuits/battery-monitor-circuit

Water Level Indicator Circuit:
https://circuits-diy.com/simple-water-level-indicator-circuit/

Police Siren Circuit:
https://www.electronicshub.org/police-siren-circuit-using-ne555-timer/
 

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Last edited:

MrSalts

Joined Apr 2, 2020
2,360
The water level circuit is complete crap - there is no resistor to limit current unless the circuit relies on the high internal resistance of the 3v lithium battery.

The siren is just a siren that continuously runs - you'll need some type of interrupt circuitry to disable the siren until you want it to blow. More than just connecting a wire to the right place.

I don't see why you would want four pots to adjust the battery monitor, four resistors in a ladder would be better and require less tuning. Look up an LM3914 and mimic the circuit inside of one of those - or use one of those.
 

KeithWalker

Joined Jul 10, 2017
2,520
Before you combine them you need to define a functional specification that describes the operation of the circuits and a sequence of events. Then you can work on getting them to interact in the way you specified.
The circuits are very fundamental for the battery monitor and level meter and rely directly on the properties of the components. The output is purely visual so it will be difficult to get a useful output from them to interact with the siren. What did you have in mind?
 

Audioguru again

Joined Oct 21, 2019
5,171
Hee, hee.
The people in India at Circuit Digest say that the LM358 is a low noise dual comparator.
Nope, it is very noisy and is a dual opamp not a dual comparator.

The water detector needs salty water not pure water.
 

Thread Starter

Swaysceptile

Joined Oct 28, 2021
16
What did you have in mind?
Is it possible to make it in a way that there's a battery monitor, water level indicator, then an alarm so that it seems like a complete system? The circuits are just examples I found because I really want the schematic to be as simple as possible since I don't have enough knowledge and understanding in electrical and electronic circuits. I apologize for the given example circuit as I thought they are good ones. I just need to make my idea into an actual circuit that works when simulated and can be turned into PCB, since this is my class main objective.
 

Thread Starter

Swaysceptile

Joined Oct 28, 2021
16
The water level circuit is complete crap - there is no resistor to limit current unless the circuit relies on the high internal resistance of the 3v lithium battery.

The siren is just a siren that continuously runs - you'll need some type of interrupt circuitry to disable the siren until you want it to blow. More than just connecting a wire to the right place.

I don't see why you would want four pots to adjust the battery monitor, four resistors in a ladder would be better and require less tuning. Look up an LM3914 and mimic the circuit inside of one of those - or use one of those.
Is there a simple way that I can combine a water level indicator circuit, battery monitor circuit, and an alarm circuit into one? I apologize for the examples I given as these are the ones I can understand and thought was enough.
 

Thread Starter

Swaysceptile

Joined Oct 28, 2021
16
Is it possible to make it in a way that there's a battery monitor, water level indicator, then an alarm so that it seems like a complete system? The circuits are just examples I found because I really want the schematic to be as simple as possible since I don't have enough knowledge and understanding in electrical and electronic circuits. I apologize for the given example circuit as I thought they are good ones. I just need to make my idea into an actual circuit that works when simulated and can be turned into PCB, since this is my class main objective.
My apologies. I was confused at first but what I meant is only combining battery monitoring circuit, Police Siren OR Water Level Indicator Circuit, and probably a blinking LED on the end.

I first stated that the Water Level and Police Siren are combined together, turns out I would only choose on either of them. Then I just need to combine with the battery monitoring one.
 

Thread Starter

Swaysceptile

Joined Oct 28, 2021
16
Is there a simple way that I can combine a water level indicator circuit, battery monitor circuit, and an alarm circuit into one? I apologize for the examples I given as these are the ones I can understand and thought was enough.
My apologies. I was confused at first but what I meant is only combining battery monitoring circuit, Police Siren OR Water Level Indicator Circuit, and probably a blinking LED on the end.

I first stated that the Water Level and Police Siren are combined together, turns out I would only choose on either of them. Then I just need to combine with the battery monitoring one.
 

Thread Starter

Swaysceptile

Joined Oct 28, 2021
16
First image is the Police Siren I created thru EasyEDA. Next is the Water Level Indicator, and lastly is the Battery Monitoring one. I was able to create the schematic, but, I don't know how I would connect the Battery Monitoring circuit with either of the other two circuits (siren or water level). If it is possible, what changes should I make? And how can I ACTUALLY connect them?

Source/s:
https://circuitdigest.com/electronic-circuits/battery-monitor-circuit

https://www.electronicshub.org/police-siren-circuit-using-ne555-timer/

https://www.pinterest.ph/pin/752030837755652405/?source=samsung_camera&oe=1

I found a newer source for the water level indicator circuit.
 

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Ramussons

Joined May 3, 2013
1,316
We have a project coming up in my Engineering Drafting and Design class and I don't have much idea yet on how to accomplish it. We are tasked to combine different circuits to design one complete device. Then we need to of course make the Schematic (and simulate it), as well as creating the PCB. I have no problems with using the software to accomplish them. I just don't know how to do the actual design... As we only did this class for 6 weeks so I don't have proper understanding of circuits and have to rely on YT tutorials.

My idea is to combine a Battery Monitoring circuit , Water Level Indicator circuit, and a Police Siren Circuit all together to form a one complete functional system that has multiple features.

Attached are the individual circuits (I found them on several websites):

As you can see, they are three different circuits. I need to combine them into one. It's no problem to go look for circuits on the internet as the main objective of my class is to improve software skills. However, how can I combine the three of them? Of course I have to modify the components but that's all I know. Not sure how to make it work.


Source/s:

Battery Monitoring Circuit:
https://circuitdigest.com/electronic-circuits/battery-monitor-circuit

Water Level Indicator Circuit:
https://circuits-diy.com/simple-water-level-indicator-circuit/

Police Siren Circuit:
https://www.electronicshub.org/police-siren-circuit-using-ne555-timer/
You have, basically 2 sensors and an alarm circuit.
Is seems that the alarm (siren) is turned on when one (or both) the sensors give the required output.
First, you will have to define the sensor output.
Your battery monitor has 4 trigger points. Under which condition do you want the alarm? Above or Below a certain voltage?
Your water level indicator ( it is quite crude, requires current limit for the LED..., nevertheless...) turns on the LED at some water level. Do you want a LOW water alarm or a HIGH one?
Once you decide on that, then we can study how the alarm circuit will be activated.

Brush up on your AND, OR and NOT logic.
 
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