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hole for mini golf

LegoAddict

Aug 26, 2015
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Hi all,

First off I'm completely new to electronics. A few months ago I had to solder a USB chip to the plug because it broke and I really liked working with the electronics at their most basic level. Now I would like to try something for a work event.

Basically we are building a mini golf set and I have an idea for one of the hole(hole will actually be an appropriate fitting doorway for a golf ball). I have a cardboard cut out of our President and CEO which I intend to put leds on it that light up if the person get's the ball through the doorway. I know I need a sensor of some kind past the threshold of the door and and a switch to the leds but that's all I know. I also have some other ideas but I think this is more than enough to start with.

Can you guys help me out? Keep in mind I'm completely new to this but I'm willing to research what I need for this.

Thanks!
 

Harald Kapp

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Welcome to electronicspoint.

The most simple sensor incorporates a switch that is actuated by the golf ball passing over it. To have the LEDs being lit for a moment (longer than it takes the ball to pass the switch), you need to increase the duration of the impulse from the switch by using a monoflop. Here is a suitable circuit including a calculator for the component values. You will need a transistor and two resistors to drive he LEDs, see this ressource.

An andvanced sensor could be made from an LED and a photosensor which would work contactless (as opposed to a switch), however, you will need additional signal conditioning (amplification, filtering) which may not be worth the effort for this gimmick.
 
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LegoAddict

Aug 26, 2015
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Welcome to electronicspoint.

The most simple sensor incorporates a switch that is actauted by the golf ball passing over it. To haev the LEDs beinglit for a moment (longer than it takes the ball to pass the switch), you need to increase the duration of the impulse from the switch by using a monoflop. Here is a suitable circuit including a calculator for the component values. You will need a transistor and two resistors to drive he LEDs, see this ressource.

An andvances sensor could be made from an LED and a photosensor which would work contactless (as opposed to a switch), however, you will need additional signal conditioning (amplification, filtering) which may not be worth the effort for this gimmick.

Thank you!

So I can't have the basic sensor set off a timed sequence of LEDs, say using something like one of those pre-programmed boards that have different sequences for leds?

Basically the ball passes over the sensor and that sets off a LED show for about 10 seconds. Just don't know what parts I need. Maybe I'm thinking this is too simple and it isn't! ;)
 

Harald Kapp

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So I can't have the basic sensor set off a timed sequence of LEDs, say using something like one of those pre-programmed boards that have different sequences for leds?
You can, if the output the light sequence after a trigger by a single short contact. If they require a constant "on" signal during the time of the light sequence, you will have to generate this prolonged "on" time from teh short pulse of the contact (switch) by adding a monostable oscillator (monoflop).
 

LegoAddict

Aug 26, 2015
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You can, if the output the light sequence after a trigger by a single short contact. If they require a constant "on" signal during the time of the light sequence, you will have to generate this prolonged "on" time from teh short pulse of the contact (switch) by adding a monostable oscillator (monoflop).


Thanks Harold, I may have more questions. I'm going to go this weekend and see if I can buy some parts for this. Would you be able to tell me what parts I need for this?
 

Harald Kapp

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From the first link in my post #2 calculate the required values, then use these and get the respective components.
You will also need a power supply for the timer circuit. The LM555 works from 5V up to 16V, so your power supply should be within this range.

You will also need the LEDs as required for your setup (color, number, size) and current limiting resistors as per the second link in my post #2. The LM555 can drive max. 200mA. If that is enough for your LEDs, you are done. Otherwise you will need a driver transistor and base resistor, see also lonk 2 in ppost#2 or this ressource for a more simple approach (no current source, just a transistor to turn the LEDs on and off, current limiting resistors are additionally required).
 

CDRIVE

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Before you purchase components please be aware that we are living in a period that permits purchasing complete modules much cheaper than you can build them from scratch. Ebay is loaded with examples of this. Here's an example of a module that can be used to stretch the LED on time as Dave explained. Electronics Point Topic

Chris
 

Harald Kapp

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Takes a big bite off the fun of building your own timer but may be just the right solution for this application.
 

CDRIVE

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Point well taken Harald, so let's ask him.

Lego, do you want to build this from scratch? Keep in mind that we'll provide you with the schematic and parts list but you will be wiring this on a breadboard where you'll have to solder jumper wires from one solder pad to another.

On the other hand I did find this 555 Timer/Osc Kit and this 555 Blank PC Board

So, what say you?

Chris
 
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