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Need help with a hammond B3 project idea.

Thread starter #21
I can answer the red/green Led issue, use a change over contact within the relay, normally closed to red, normally open to green, and common to + supply.
Yes one got that part. " I previously said The relay would get 5 volts to the coil when the switch was active or closed and the normally open contact would close turning on the green lights when the Leslie was spinning fast then when the switch is opens the coil would not get the five volts and the normally closed contacts would close turning on the red LEDs lights . The leds will be powered separately and sized appropriately to the relay specs and LEDs I use." Can you suggest a way to power that relays coil n I'm not sure I know what you mean by change over contact do you mean the side of the relay with the contacts? Thanks for your input I appreciate it
 

eTech

Active Member
#22
If I use wall warts to power the LEDs what did you Invision in terms of the device/component that would switch them. Keeping in mind that I'm trying to let the player look down and by seeing either a red glow from LEDs (when the Leslie is spinning slowly and therefore no voltage present at the switch) or a green glow when the Leslie is spinning fast, voltage.... Wait as I wrote this it occurres to me that voltage is present at the switch in either state it's just current that is flowing or not... Just a thought. Back to the problem what do you suggest I use to trigger or power the coil in the relay. Or is there another device or type of relay I could use.
I never anticipated this being easy but also never thought it would be as complex as it is seeming.
I am an electrician and appreciate your comment on care being used when routing 120volts at the pedal.
If I'm looking in the wrong direction due to my ignorance of electronics I'm open to any ideas using any components out there to accomplish this. I just hope I understand anyone's suggestions so that I can implement them.
This is fun and I thank you all
Hi

I've looked at the wiring diagrams provided in post #16. Unfortunately, none of them shows the wiring inside the foot pedal, and that's what we really need to see.

I'm thinking of three approaches.
1. Two Wall wart approach (inside pedal)
If there is room in the pedal, you could mount two small AC-DC wall warts inside the pedal. One side of each wall wart AC input would connect together and attached to non-switched AC. The two remaining AC supply wires would connect to the fast or slow side of the switch so that only one or the other wall wart will be powered based on the position of the foot pedal. Then use the appropriate DC output to light the corresponding LED strip. I don't like this....its clunky....but it might be doable.

2. One Wall Wart and two Opto-Isolator approach (inside pedal)
One AC opto-isolator can be connected to the fast and one to slow side of the switch to detect AC. The wall wart would connect to non-switched AC in the pedal. Each opto would detect AC based on the position of the foot pedal. When AC is detected, a relay or mosfet would energize the appropriate LED strip using the Wall Wart as a DC power source.

3. Wall wart at Leslie.
This is basically the same as #2 above except the new components are located at the leslie and three DC supply wires are run from the Lesie to the footswitch where they can be attached to the LED strips. This approach may not require opto's. It doesn't say on the schematic the type of relay REL1 is, but might be able to parallel connect a wall wart, or additional relay, to REL 1 connections. Then use that to switch the LEDs. This is probably the cleanest approach but it does require running new wires from the Leslie to the pedal.

We still need to see a wiring diagram of the foot pedal.

All I can think of for now..hope that helps..

eT
 
Thread starter #23
The pedal really is very simple. It has a100k potentiometer that gets signal from the peanut if the organ m I do not want to alter it or in any way modify that part of this. There is also a simple soft touch sp latching pushbutton. It is through this pushbutton that 120 volts is switched in and off. That voltage comes, by way of the organ, from the Leslie speaker which sounds fast when the switch is closed and sounds slow when the switch is open. A schematic for the pedal would show just those 2 items
I hope that helps.
I suppose I could use a relay with a120 volt coil tapped if the switch but I thought and still do that there must be a better and quieter way to do this.
Sparky
 
Thread starter #24
If you want to make sure the relay coil remains 'quiet'.
Put a 1n4001 diode across the relay coil, with the cathode (silver stripe) on the diode to the positive side, orientation here is important.
Then place a 100nF x7r or similar capacitor in series with a 100 ohm 1/4 watt resistor in series across the coil, orientation is not important.
This should make clicks go away, its also a good idea to have the power for the relay coil to be on a seperate cable, if you run the relay coil signal in a screened cable along with audio you heading for clunks & clicks.
So the diode goes across the relay coil and the capacitor/resistor goes in series, before or after I am guessing before the coil? I'm confused by the term "in series across" the coil. I thought in series would not be across but in line with the coil either before or after it.
Thanks
Sparky
 
#25
Whoa that PDF is very interesting but way over my head I think I'm rereading it again but I can't help but be reminded that at one time the B3 expression pedal used a optical resister or I think that what it was called. It was an actual small lamp and a photo sensitive gizmo with a divider between then that had slit in it that widened as it moved down with the pedal our vice versa. I have one out in my shop but can't find a picture. The closest I could find is the replacement lamp that is soon being sold for today that need it and the info on that I'll paste it here ”Expression pedal lamp for Hammond E-100/200/300, H-100/200/300, L-100 and Porta-B series organs. Replaces Hammond part number 016-031748. Failure of this lamp will cause the organ to operate at full volume regardless of expression pedal position”
JeffGee: Sorry if it was 'over the top'. In simplest terms, that's similar to what the optical resistor is, with the exception that the bulb brightness
controls the resistance of the photo cell.

The 4 diodes would be in this package.
https://www.circuitspecialists.com/df06.html

There are 4 pins: 2 of them are for AC in. The other 2 are the DC output (+-)
The switched side of the footswitch would go to one of the AC inputs of the little gizmo. The other AC input would go to the neutral.

A Capacitor on the DC side will filter out the line frequency (Just like in a power supply).

You would use this IC.
https://www.vishay.com/optocouplers/list/product-83433/tab/specifications/

Here's a schematic.
120VOpto.jpg

Be very careful around the bridge rectifier! It's 120VDC, and can kill you.
 
Thread starter #26
Thanks so much for your help. I think I understand this well I know I understand it better than the other. I feel badly but I do see a problem. But before I tell you that let me ask if I can buy this device represented in your schematic off the shelf. It seems I could but you would know more than I. Now the problem is that at the pedal specifically at the toe switch there is no neutral. It is just the hot leg that is brought down from the organ to the switch so it can be (opened) and closed. I think I can find the neutral that is associated with it but I'm not sure and don't want to alter the circuitry of the organ. As I wrote this it occurres to me that without that neutral I can't power a coil in any case. The plot thickens... Again
Hmmmm
Thanks
Sparky
 
#27
Hi Sparky

Can I ask a question, out of curiosity .. .. .. .. .

Is it the organist's wish to have the lights around the pedal ? I would have thought the indication would be much easier to see if it were placed on the console somewhere ?

S
 
Thread starter #28
That's a great question. And I've u an going to ask him. But he did in fact ask for the lights to be in the pedal. Thinking about the lights being on the organ itself, which by the way is aB3 "chop" single manual but with all four sets of draw bars, I think it would be easier. Did you have an idea for that scenario? Thanks in any case.
Sparky
 
#29
But he did in fact ask for the lights to be in the pedal.
How times change .. .. .. when I was a student, which granted, was just after the Romans invaded Britain, I was taught never to look at my feet.

Did you have an idea for that scenario? Thanks in any case.
Maybe .. .. ..look here ..

Leslie-1_gzxbfj.jpg


I would place a small IR sensor where the red arrow is ( google HOA 1405-2 ) and paint 10 white dots spaced equally on the bottom edge of the sub-woofer. The RPM range of the subwoofer, from memory is about 50 - 500 RPM; It would be very easy to tell a small Arduino to turn on a Red LED at 70 rpm and at 400 rpm a Green one. You could even use an LED Bar Graph and have 10 gradual indications. The only power issue you would have is providing 9 -12vdc for the Arduino - could even be done with a battery, although it may not last too long. I would site the LED's on the console, but you could use the Arduino to turn on/off strips of LED's in the pedal area via a suitable transistor.

I know the Arduino code may be a concern, but there are loads of examples on the net and plenty of folk in here to help you get it as you'd want it.

Maybe an alternative approach to think about .. ..

S
 

dr pepper

Well-Known Member
Most Helpful Member
#30
The diode goes across the coil, stripe to +, other side to -.
And connect one leg of the cap to the coil connection (either side), then connect the other leg of the cap to the 100r resistor, then connect the other end of the 100r to the remaining coil connection.
 

eTech

Active Member
#31
How times change .. .. .. when I was a student, which granted, was just after the Romans invaded Britain, I was taught never to look at my feet.



Maybe .. .. ..look here ..

View attachment 116135


I would place a small IR sensor where the red arrow is ( google HOA 1405-2 ) and paint 10 white dots spaced equally on the bottom edge of the sub-woofer. The RPM range of the subwoofer, from memory is about 50 - 500 RPM; It would be very easy to tell a small Arduino to turn on a Red LED at 70 rpm and at 400 rpm a Green one. You could even use an LED Bar Graph and have 10 gradual indications. The only power issue you would have is providing 9 -12vdc for the Arduino - could even be done with a battery, although it may not last too long. I would site the LED's on the console, but you could use the Arduino to turn on/off strips of LED's in the pedal area via a suitable transistor.

I know the Arduino code may be a concern, but there are loads of examples on the net and plenty of folk in here to help you get it as you'd want it.

Maybe an alternative approach to think about .. ..

S
Yes....I suggested something similar in the back in the first few posts but using a different circuit. I'm a musician also and after thinking about it, I wouldn't want to be distracted by the lag caused by the spinup/spindown of the motors. For example...you step on the pedal and then wait for a few seconds for the lights to change. Or maybe you thought you stepped on the pedal but didn't, so you keep glancing at the lights...all while trying to perform...

I don't know....i'd rather step on the pedal, have a light turn on instantly, and let my ears do the rest....:happy:

eT
 
#32
I'm a musician also and after thinking about it, I wouldn't want to be distracted by the lag caused by the spinup/spindown of the motors.
Agreed, but then, having grown accustomed to playing an instrument that populates several 'rooms' in a building, I wouldn't want to be distracted by a Hammond Organ .. . but that's irrelevant to this discussion.

The OP would have to confirm this, but as I understand it … the Leslie is On or OFF via a simple switch on the console; if ON the cones are rotating either slow or fast, controlled by the switch installed on the pedal, not the pedal itself which is concerned with volume only.

I take your point about the time lag, although I don't think its as significant as 'a few seconds'; the bar graph LED option would probably deal with that.

I do think it's important to avoid any option that involves switching mains voltage, especially where there is a 'hit & miss' possibility as in a foot pedal.

As an example, some years ago, I turned up to provide organ accompaniment for a funeral in a country church. At one point, the entire congregation was seen to levitate about 3 -5 inches in unison as a result of a very loud 'crack' through the organ speakers caused by someone turning on a projector. A change of underwear may have been essential !

I don't know....i'd rather step on the pedal, have a light turn on instantly, and let my ears do the rest....:happy:
Absolutely ! :)

S
 

dr pepper

Well-Known Member
Most Helpful Member
#33
Agreed about switching mains, not just for safety, the life of the switch as well, mains is going to generate a flash every time & wear the contacts down, esp with an inductive load such as a little motor.
 
#35
JeffGee: The lack of a neutral is definitely a problem.

I had an idea, which would completely isolate your pickup circuit from the B3 circuitry.

Take a look here
https://www.mouser.com/datasheet/2/336/P698-1006329.pdf

Here's an explanation.
https://www.digikey.com/en/articles/techzone/2012/sep/the-basics-of-current-sensors

All you need to do is to disconnect the switched side of the foot switch and thread the wire through the current sensor.

Then solder it back to the switch. :)

Basically, when the switch is on, the current sensor will pick up the AC and produce a signal.
SInce you need a power supply for the leds, you can use this and put a circuit together that would turn the signal from the sensor into a digital drive signal (LM339 Quad comparator maybe? )

It still needs some thought.
 
Thread starter #37
Thanks for this. I was kind of thinking about something like that once it hot me that i had no neutral in the pedal So i have a couple of these coming
Screenshot_20190205-023337.png and

https://m.banggood.com/DC-12V-5A-Ov...d=10249984&sc_lid=104858042&sc_uid=CY2yAIUngB And I have started my Arduino education.
What do you think of this module an i going down a wing path or?
Thanks for sticking with me on this one too everyone who has contributed to this process
Sparky
 
#38
JeffGee: That particular module is designed to sense an overload. It looks like it needs to have its' power recycled when it senses AC current above a certain value.

Take a look here.
https://www.ebay.com/itm/Single-Pha...tput-Voltage-Sensor-for-Arduino-/153093732593

Since you'd have to cut the wire anyway, you might as well use one of these. This module will sense the presence of AC voltage, and produce
a sine wave at a much lower amplitude. (0-Vcc, with Vcc / 2 being the half-way point. It goes in series with the switch wire.

That's easy to fix, as a capacitor in series (100nf ceramic @50v should be fine) will block the DC and allow the AC to pass.

Remember: The sine wave will only be Vcc at most, and at very low current; It's as safe as it can get. :)

At that point, all you have to do is set up a half-wave rectifier (a diode and a cap.) and you should have a gate out that can be used to switch things
on and off.

Easy Peasy. :)
 
Thread starter #39
I thought i posted a reply yesterday or the day before but I'm not seeing it. I just got home from work, it's 9am in northern California and i have to crash. I'll try and find my reply or post a new one. I think we are edging closer to solving this one. I thank you all for your continued help.
Peace
Good night or wherever
Jeff
 

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