Buzzer

[rthuey]

i purchased this piece and planned on it triggering a buzzer. turns out normal state for the output is a digital high and then it goes low when it senses an object. i was expecting it to be the other way around and i would use the power to activate the buzzer. i could use suggestions on adding the buzzer to make the complete circuit i intended.

 

[KMoffett]

Interesting, I can't find any spec's in the ad's or datasheets for the maximum output current drive capability of the modules. What are the voltage and current requirements of your intended buzzer?You could just add a resistor and PNP transistor to drive the buzzer.

Ken

 

[colin55]

What type of buzzer do you have?

 

[rthuey]

this buzzer is the initial one i will try.

volt = 3v
free run current = 60ma


Supply voltage VCC -0.3 to +7 V
Output terminal voltage VO -0.3 to VCC+0.3 V

@KMoffett is this the current info you were looking for?
Parameter Symbol Rating MIN. TYP. MAX. Unit
Average supply current ICC1 VCC=5V, Vin=5V, R1=4.3Ω (*1) ― 5 6.5 mA
Average supply current ICC2 VCC=5V, Vin=5V, R1=4.3Ω (*1) ― 9 10.5 mA
Stand-by supply current ICC3 VCC=5V, Vin=0V ― 5 8 μA

 

[KMoffett]

There is still no spec there on the maximum current available at the module's output. So, here's a circuit that should require very little drive current to switch on your vibrator.

Ken


This is a bad design...please ignore! I corrected it in post #11.

 

[rthuey]

tanks for the fish Kmoffett. it was delicious and works. even though i put another buzzer in there since the one i listed in the earlier post is not here yet. the circuit appears to be wonky. i can not find a spec sheet for it. all i know is it is 3vdc micro vibration, rs #273-107. perhaps different resistors for this particular buzzer are needed?!?
i guess i asked the wrong question initially anyways. is it possible to get some instructions to build the rod to do my own fishing? perhaps a brief overview of how the pieces in the circuit are working together may help. i would like to try and figure the adjustments needed for this motor.

 

[KMoffett]

tanks for the fish Kmoffett. it was delicious and works. even though i put another buzzer in there since the one i listed in the earlier post is not here yet. the circuit appears to be wonky.

So, does it work or not?

i can not find a spec sheet for it. all i know is it is 3vdc micro vibration, rs #273-107. perhaps different resistors for this particular buzzer are needed?!? .

From a general Google search, that type of motor draws about 75mA.

i guess i asked the wrong question initially anyways. is it possible to get some instructions to build the rod to do my own fishing? perhaps a brief overview of how the pieces in the circuit are working together may help. i would like to try and figure the adjustments needed for this motor.

First, what symptoms do you see that indicates that the module is working, the motor is not working.

Ken

 

[rthuey]

yes it works, sporadically. sporadic as in when it acknowledges an object and activates the buzzer. no light and no buzzer.

module vs motor - module by itself on breadborded circuit. pass an object in front of it and the light comes on as it should indicating it is sensing the object. meter on it and with 4.5v coming into the module the out has 4.0v, no object in front. the out changes to .5 - 1v on the out when an object is placed in front and the led lights on the module indicating it senses the object.
module with the motor. initially was sporadic but i figured it was breadboarded and not all connections were solid. after i assembled the circuit on a pcb and soldered it improved a bit, not so sporadic. the assembled piece is using a 3v cr2032. no load on the out is 2.8v and i can't coordinate an active sense with the meter leads touching at the same time for a reading.

how did you come up with the pieces in the circuit that you did with the information given? did you use the 60ma free current or another number?

 

[KMoffett]

From your original link:

The square pad is ground, the middle pad is VIN (2.7 – 6.2 V), and the remaining pad is the sensor output, OUT. Depending on your power source, you might notice an increase in performance by placing a large (>10 uF) capacitor between power and ground somewhere near the sensor.

using a 3v cr2032. no load on the out is 2.8v and i can't coordinate an active sense with the meter leads touching at the same time for a reading.

What's the supply voltage when there is a load? It looks like you may be pushing things beyond their operating limits. Remember the module's average current may be 5mA, but it draws a pulsing current of ~70mA. Adding the LED and motor currents may be pulling down the battery below the module's minimum operating voltage (2.7v).

Ken

 

[alec_t]

may be pulling down the battery below the module's minimum operating voltage.

I'd agree with that. A CR2032 won't provide much current for very long.
One quote on the web says "CR2032 coin cells are usually rated for 15mA peak current"

 

[KMoffett]

ARG! Don't know what I was thinking in my previous schematic. Too many distractions. Should not have drawn an emitter follower. This should work better. But will still not get around you low battery current capacity problem.

Ken

 

[rthuey]

supply voltage when there is a load is 3v at the module Vin and at the buzzer + lead. (No? I have a 3v battery. Unless i am missing something in the question.)

the led is built into the module. i would hope any specs they gave on average current would include their own led. it states that max average current supply is 6.5 or 10.5
when would the pulse current of 70ma be seen?

this says a cr2032 has 220 mah. no mention of peak current.

would i use 3v/220mah to calculate how long the circuit can be alive?

the buzzer lists a free run current of 60ma
the module lists max average current supply of 10.5ma
do these two numbers get combined to calculate how long a battery will last?


saw your latest post after submitting this.

looks like same parts different configuration.

 

[KMoffett]

supply voltage when there is a load is 3v at the module Vin and at the buzzer + lead. (No? I have a 3v battery. Unless i am missing something in the question.)

Terminal voltage can drop significantly under a heavy load.

the led is built into the module. i would hope any specs they gave on average current would include their own led. it states that max average current supply is 6.5 or 10.5
when would the pulse current of 70ma be seen?

If you check the Sharp datasheet, the LED in the detector head is typically pulsed at 70mA.https://sharp-world.com/products/device/lineup/data/pdf/datasheet/gp2y0d805z_e.pdf

this says a cr2032 has 220 mah. no mention of peak current.

would i use 3v/220mah to calculate how long the circuit can be alive?

the buzzer lists a free run current of 60ma
the module lists max average current supply of 10.5ma
do these two numbers get combined to calculate how long a battery will last?

https://www.electro-tech-online.com/custompdfs/2012/06/cr2032.pdf According to Energizer's datasheet their 240mAH rating is based on a 15KΩ load...that's only a 200µA load.

saw your latest post after submitting this.

looks like same parts different configuration.

Yes.

Ken

 

[rthuey]

the schematics you have shown marked the buzzer 3v/60ma. does that put the buzzer at 50ohms of resistance? are you using an online circuit simulator? or does it just draw? i was trying to use the one at circuitlab.com

 

[KMoffett]

Just using my brain (not always at peak performance), my experience, and ExpressPCB for the schematic.

Ken

 

[rthuey]

with that last schematic and the originally planned buzzer in place.

using the breadboard with a feed of 3v or 4.5v and just the module, the sensor responds as advertised both times. 10 min ago and the other day. then went back to take readings and 3v was stuck on.
3v = Vin 2.6v + Vout .6v w/sensor stuck in on.
4.5v = Vin 4v + Vout 4v w/inactive sensor. Vin 3.9v + Vout .6v w/active sensor.

3v, module and schematic - the led on module stays on. which should also indicate the sensor is being activated. no nothing is in front of it. Vin is 2.7v and Vout is .9v

4.5v, module and schematic - sensor works as advertised. Vin is 4v w/inactive sensor, Vin is 3.7v w/active sensor. Vout is 4v w/inactive sensor, Vout is 1.5v w/active sensor.

 

[KMoffett]

What is "Vin"? Is that the battery/supply/Vcc voltage?

Ken

 

[rthuey]

on the module there are 3 connections available, OUT, VIN and GND. Vin is where i was taking the readings from.

 

[KMoffett]

Well since the Vin is spec'd at 2.7V minimum, it's not likely to work properly with a 3V supply that is dropping to 2.6V . And I assume that you are reading an "average" measurement with a voltmeter. Since the LED pulse current is 70mA for eight 20us intervals (seen only with an oscilloscope) it is likely pulling the instantaneous voltage even lower than that. You need higher capacity batteries.

Ken

 

[rthuey]

so i found a couple cell phone batteries laying around that i am considering using instead of the coin battery. i would be able to pull them from the finished circuit as needed and throw into the phone to charge. BT51 - 3.7v and 950mAh. There are 4 contact points and if i put the red wire from the volt meter on the one closest to the + mark and the black onto the next contact to the left i get 2.8v, first contact to third i get 4.2v, first to fourth i get 4.2v.

I connected the schematic and module to the first and fourth. Works as advertised. Vin is 4.2v w/inactive sensor, Vin is 4.3v w/active sensor. (Yes i double checked) Vout is 4.2v w/inactive sensor, Vout is 1.7v w/active sensor.