I am wanting to make a Digital volume control that does not require amplification. I basically want to use it with 3.5mm audio jack in, and 3.5mm audio jack out, with the ability to fade the volume down via digital push button until no audio can pass through, and then obviously have the ability to fade the volume back up again via another digital push button.
The simplest thing I have found so far is to use a DS1802 potentiometer but am unsure of a couple of parts used in the image circled (apart from the 5v regulator.

http://imgur.com/2QamIjK

http://electrodb.ro/forum/atelier-gr...1802-thread23/

Also If anybody knows of a simpler/cheaper way to make a digital button volume control i would love to hear it.

 

That appears to be a good part to use as a audio level control. What are you unsure of in the image?

 

I am unsure what type of capacator is used and also the type of 3 pin TO92. their website has a diagram but I'm not too sure how to figure out those two parts that are required?

 

it appears to me that parts on board consist of:
1 x DS1802
1 x Molex
1 x 5V Regulator
2 x 3.5mm jacks
1 x TO92 ?
1 x Capacitor ?

 

I am wanting to make a Digital volume control that does not require amplification. I basically want to use it with 3.5mm audio jack in, and 3.5mm audio jack out, with the ability to fade the volume down via digital push button until no audio can pass through, and then obviously have the ability to fade the volume back up again via another digital push button.
The simplest thing I have found so far is to use a DS1802 potentiometer but am unsure of a couple of parts used in the image circled (apart from the 5v regulator.

http://imgur.com/2QamIjK

http://electrodb.ro/forum/atelier-gr...1802-thread23/

Also If anybody knows of a simpler/cheaper way to make a digital button volume control i would love to hear it.

No, this is wrong implementation for sure. DS1802 is great part, and Pedja Rogic presented long time ago right implementation, but pages are not alive, so here is his complete text with schematics.

The DS1802 is the dual audio 45kOhm (typically) pot with 65 steps (64x1dB and mute), known around for its possibility to be controlled by its own pushbuttons instead of, usually needed, certain logic circuitry. It is available in DIP package and hence seems very appealing for DIY. However, there are a few issues to be considered about its usage in the audio amplifiers.

Most of the digital potentiometers (there are exceptions like WM8816 and X9312) can not accept signals much beyond their supply voltages. For DS1802, 0.5V below the potential at its Gnd pin is the bottom, and 0.5V above the Vcc (whose safe maximum is 5.5V above the Gnd pin) is the upper limit. There are a few ways to center the signal inside these boundaries and Dallas recommends Wheatstone-Bridge circuit (see App Note 161). I decided to shift the supply rather than signal, thus with one more regulator I could keep the signal path clean. So, DS1802’s Gnd pin went down to -2.5V and all the other pins of DS that normally should go to ground went to this pin: Agnd, Zero-Crossing (enabled) and Mode (stereo), as well as the Up/Down buttons. Resistive networks themselves are connected straightforward. The DS1802’s pin layout appeared almost ideal for such application.

Note that the DS1802 will not, working with shown supply (you can try to push it harder but you will do that on your own risk), accept the conventional output level of the CD players. It will certainly clip with usual 2V RMS and more, and with such sources DS1802 is unusable unless you decide to attenuate the signal before it enters the pot (in my view this approach does not have much integrity though). Clipping is instant and very unpleasant but generally all is well as long as it does not occur. So, a lower voltage at the pot input is a must. This, however, won’t be that bad for those using common base based or purely passive I/V converters in their CD players – almost always such kinds of stages will be happy to develop lower voltage.

Another problem might be the absence of the visual identification of the actual pot setting, however to include the display, much more engagement than described here is needed.

The circuit is simple, put it together, listen to and compare to some expensive audiophile volume control solution, you might be nicely surprised. Blue ALPS can not equal that precise soundstage and that female voices. Dynamics is excellent. One might find ALPS more natural but for me this silicon part had more good sides. Even if you take into account 2 regulators and caps (assuming you can steal raw voltages somewhere in the unit they are used in), price stays quite modest. High input impedance of the next stage is recommended. In my case the DS1802 drove the buffer whose input impedance was set to 50k. At the pot's input side, as expected, my EF86 anode follower failed to drive it (dynamics collapsed, 45kOhm and wiper loaded with 50k is too hard for this tube) but the diamond output stage of the AD844 did it happily. Cheap high end. Recommended.

 

Thank you for your assistance.
I thought the DS1802 would only accept 3V to 5V supply, but this shows 15V input unless I have misread something?
If it is 15V What type of 1.5K resistor should I be using and what ?V 100u capacitors should I be using?
I was hoping to use a 5V power input such as, from a usb plug.
I am New to electronics but am trying to learn and understand. I have don'e some research since your post but have currently hit a wall as far as my understanding is concerned.

 

Thank you for your assistance.
I thought the DS1802 would only accept 3V to 5V supply, but this shows 15V input unless I have misread something?
If it is 15V What type of 1.5K resistor should I be using and what ?V 100u capacitors should I be using?
I was hoping to use a 5V power input such as, from a usb plug.
I am New to electronics but am trying to learn and understand. I have don'e some research since your post but have currently hit a wall as far as my understanding is concerned.

And I was thinking that text with schematic is totally clear without any doubts.

DS1802 can work on 5V, but you can push it higher if you have cliping problem. If I remember right, in datasheet there is defined 5.5 V as max. I was running my on 6V, but it is up to you, break the chip I don't care.

Pedja Rogic used most elegant way to have right supply and untouched audio signal. He used TL431 as 2.5V regulator, two of them for total of 5V. Supply voltage (15V at TL431 input) can be much lower, 3V will be just fine, and resistor value is related to this voltage and DS1802 current.

If you want to build the toy, there is no problem with using 5V USB suplly, and use DS1802 powered by 5V with destroyed audio signal. If you want real staff, than use Pedja Rogic solution, and for 2 x 3V for supply can be used almost any dumped mobile phone charger (better with real transformer not switch).

 

Ah. Thank you very much. This clears things up for me and gives me a better understanding of the schematic. Much appreciated.

 

can you buy +/-15v power adapters or do I have to make one for this?

 

can you buy +/-15v power adapters or do I have to make one for this?

As I already mention in last post, you don't need +/-15 V. Pedja Rogic chose this value because it can be found inside most hi-fi devices, so extra supply is not needed.

You can use anything higher than 3V. For example 2 x 5 V will be just fine. You can find on trash or as second hand (free) all kind of low voltage transformers (3V - 6V) that are used for cell phones, hair trimmers...