Have any of you has build a MIRT? Do they really work?

[Turbo_Boss]

Sorry, I drive beaters so I don't have to spend money on fancy alarm systems. I can't even remember the last time I made a car payment, it might have been 1991 or thereabouts.

Hey Papabravo, Ok forget about the fancy alarm. Help me with the following: I want to make a delay circuit that "maybe" can use a 555 IC. What I mean if you know how to do this circuit without the 555 is OK for me.

I have look a lot of 555 circuits on the net but dont find what I am looking for.

This is what I want:

A relay coil that get energized only when a momentary switch is keep pressed for more than 4 seconds and keep energized untill I release the momentary switch. If I press the momentary switch for only one or two seconds the relay coil will not get energized.

Do you need aditional info for this circuit let me know.

THX so much,

Isaac

 

[Papabravo]

I'm not real good with 555's and relays. If I had to do it I would use a PIC. That way is trivial for me because I know how to do it that way. It may be more difficult for you though.

It's funny, but in 37 years of hardware design I've never actually built a circuit with a 555. I've seen lots of them and read about them, but never had occasion to design with one.

 

[mramos1]

Turbo_boss: google for 555 online calculator. You will fine the calculations, configurations, etc. There is a ton of 555 stuff.

If it was me, pic as well. I did a 555 circuit way back and do not even recall what it was for. They seem to be popular among the non-electronics (non-programming type) people for sure.

 

[philba]

I'm usually biased towards uC as well but a 555 is an amazingly versatile chip. If you are set up to use PICs or AVRs or similar, I'd say go for it. However, if you are staring at a learning curve for uCs, go with the 555.

Of course, a lot depends on exactly what you want to do with it. note that the uC design will be much more flexible - changes only take programming.

 

[Turbo_Boss]

However, if you are staring at a learning curve for uCs, go with the 555.

Thats is my problemo, I really dont know to much electronics and thats why I am asking if any of you can give me the schematics of a circuit using a 555 with all the component values that will do what I need. I have build several electronics things just following the schematics.

Here is what I need:

I can use a 555 timer circuit to keep the horn from sounding unless it receives power from the alarm for more than 3 seconds. That way the horn will not sound during arm/disarm. The horn will take 3 seconds to sound during alarm.

The 555 timer circuit can take the signal from the 12V+ wire that drive the siren and wait 3 to 4 seconds to energize a relay that when the contacs close it allow the alarm horn wire to conect with the car horn.

Could it be posible that you guys help me with a a schematic of this circuit with his respectives R and Cap values?

They relay that I have with me for this project is AXICOM D2n
200 mW nominal power consumption

Nominal Voltage----------------------- 12 Vdc
Operate/Set Voltage Range------------ Min Vol 8.4 Vdc
Operate/Set Voltage Range ----------- Max Vol 27.9 Vdc
Release Reset Voltage Minimun-------- .060 Vdc
Coil Power --------------------------- 200 mW
Coil Relay Resistance ---------------- 720 oHM ± 10 %

Thank you so much for your time and help,

Isaac

 

[philba]

Could it be posible that you guys help me with a a schematic of this circuit with his respectives R and Cap values?

**broken link removed**

 

[Hero999]

I'm usually biased towards uC as well but a 555 is an amazingly versatile chip.

The thing I like about the 555 apart from it simplicity and low cost is that it can source and sink 200mA, more often than not you end up with a single semiconductor device solution.

 

[Turbo_Boss]

**broken link removed**

Which one I have to use???

THX,

Isaac

 

[philba]

Which one I have to use???

THX,

Isaac

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