Spark Plug - problems continuing electrical current

Danerds · Post by **Danerds** » Wed Apr 25, 2007 2:22 pm

Howdy y'all, were making a Spark Plug. We have constructed it word for word according to your directions. However, it still doesn't work. We have tested all of the wires with a lightbulb, seeing if the lightbulb lights up when the two wires from the battery touch it. All of the wires before the capacitor work. However, the two wires that come after the condenser/capacitor that connect to the primary coil and the Neef Vibrator don't work. In other words, there is no electrical current. Is this do to a problem with the capacitor conducting electricity or is it with the Neef Vibrator not working properly (And yes we have already broken the neef vibrator out of its plastic housing and cut the two wires that attach the hammers to the soft iron core thats already in the Neef Vibrator). Please respond fast, like a rabbit.

Thanks y'all!

Craig_Bridge · Post by **Craig_Bridge** » Wed Apr 25, 2007 3:11 pm

The primary circuit should contain in series, the battery, the primary coil (hope you used insulated wire) wrapped around the bolt, the "common" relay contact, internal normally closed to, the "normally closed" contact, one side of the momentary contact push button switch, depressed switch to make internal connection, the other side of the momentary switch back to the other battery contact.

The capacitor should be in parallel with the "normally closed" contacts which should be shorting it out at the starting point in time. The capacitor doesn't matter until the contact opens at which point it prevents the voltage from changing immediately which will keep the current flowing for a very small amount of time while the capacitor charges.

Hook you light bulb across the "open" (not depressed push button) momentary contact push button switch and it should light. If it doesn't, you have something mis-wired. Maybe you used the wrong contacts on the relay? You need ones that are normally closed. The bolt / primary coil should be an electro magnet that is used to "open" the relay contact by attracting the "iron or steel" spring loaded contact just like the original primary relay contact coil did in the original unmolested relay.

As the capacitor charges, the current will decrease and the magnetic field will collapse, the relay contacts will close and short out and discharge the capacitor and the cycle should repeat as long as you have the push button depressed.

Danerds · Post by **Danerds** » Wed Apr 25, 2007 3:35 pm

I will try this and I will respond either tonight or within the next day.

Danerds · Post by **Danerds** » Thu Apr 26, 2007 7:20 pm

Every thing is hooked up correctly (at least to my knowledge it is) but the hammer from the neef vibrator isn't clattering. Any suggestions?

Craig_Bridge · Post by **Craig_Bridge** » Fri Apr 27, 2007 11:01 am

If you move the bolt away from the relay and depress the push button, will the bolt attract a steel nail, nut, washer, or other iron object? If not, you need to trouble shoot the electro magnet. Did you use insulated wire for the primary coil? Did you use a soft or mild steel bolt (stainless, bolts with hardness markings, and brass will NOT work)?

If the bolt attracts steel/iron, then you need to figure out why it isn't attracting the relay contact to open the circuit. Try using a magnet to see that you didn't destroy whatever the unmolested relay coil was designed to attract.

Danerds · Post by **Danerds** » Sat Apr 28, 2007 6:19 pm

We have tested the bolt and it is indeed magnetic when the button is pushed. However, we still can't get the hammer on the Neef Vibrator to vibrate. Any suggestions?

Craig_Bridge · Post by **Craig_Bridge** » Sun Apr 29, 2007 9:45 am

Ok, so the electromagnet is working, this means that the initial state of the circuit is valid. Did you follow these previous suggestions?

If the bolt attracts steel/iron, then you need to figure out why it isn't attracting the relay contact to open the circuit. Try using a magnet to see that you didn't destroy whatever the unmolested relay coil was designed to attract.

The relay contacts have to open in order to vibrate. What you have to figure out is why the part in the relay that is supposed to be attracted by the relay coil isn't being attracted to your bolt.

The attractive force of the magnetic field of the bolt is a function of the current, the number of turns, and the inverse square of the distance away from the end of the bolt.

The attractive force may be too small, distance maybe too large to overcome the spring force of the relay contacts that force it to switch to the normally closed state, or the distance may not be great enough to allow the contacts to to move far enough to open.

You may also have a wiring error at the relay contacts. What happens if you insert a piece of paper or toothpick between the normally closed contacts? Does your test light placed across the push button contacts still light? It should only light when the normally closed contacts are "made" (making contact) and should go out when you insert the piece of paper or toothpick and "open" the contact.

Craig_Bridge · Post by **Craig_Bridge** » Sun Apr 29, 2007 3:38 pm

Several investigators have had difficulty with this project so I went out and bought the Radio Shack 375-0217 relay called for in the parts list. The sample I purchased was actually an OMRON LY2 series relay.

The step 6 project instructions:

Making the Neef-type vibrator will require some ingenuity on your part. To construct a Neef-type interrupter, you will have to break the relay from its plastic box and use a part of it for your experiment. A relay usually has a two contact plates separated by a hammer and an iron core. Depending on the voltage applied, the hammer can be in contact with either of the plates on its sides, thus completing one circuit and breaking other. For our purpose we don't need the core from the relay, (because we will use the core that we have constructed). We will need the two contact plates and the part of the hammer between them. We will use this contraption such that the hammer remains in touch with one of the contact plates until the magnetic field from the activated core pulls it away, breaking the contact and the circuit.

Are problematic at least for the sample relay I'm looking at which is an inverted U frame with a plastic bobbin coil on a core staked through the long side of the U. The short side of the U is actually a spring loaded hinged piece that is ultrasonically welded to the plastic holding the common copper spring contacts.

It looks like it will take more than a little "ingenuity on your part" to modify the hinged spring loaded contacts in this particular relay to work with the bolt called for in this project.

I'll have to think more about the mechanical design aspects and see what I come up with.

Craig_Bridge · Post by **Craig_Bridge** » Sun Apr 29, 2007 4:13 pm

If you can't come up with a way to modify the relay parts that you have to utilize the bolt as the "core" electromagnet, you might want to consider a 12 VDC "relay chatter" interrupter design. It takes a few more parts (second battery and a new relay) but you don't have to modify the relay!

The Radio Shack model 275-218 relay has a 12 VDC coil and has the same contacts (basically just a different coil with more turns and smaller wire).

Draw out the circuit I'm about to describe using a copy of the existing schematic. Draw the new battery to to the right of the existing line going up to the primary coil. Draw a new coil (the one inside the new relay) to the left of the existing contacts. The new line from the new battery to the new coil should be drawn below the batteries. What you should end up with is three "loops" excluding the forth high voltage secondary loop with the spark gap in it.

The following instructions assume that the "red" battery terminal is the positive or "+" terminal and the "black" battery terminal is the negative "-" terminal. Up to now, it really didn't matter, but it will if you add the second battery!

Connect the positive contact of the second 6 volt battery to the existing negative battery contact and the primary coil. Connect the negative contact of the second 6 volt battery to pin 7 of the 12VDC relay coil. Connect pin 8 (the other 12 VDC relay coil contact) to pin 5 (a common relay contact), one end of the capacitor, and the other end of the primary transformer coil. Connect pin 1 (the normally closed relay contact associated with pin 5 common) to the other capacitor lead and the momentary switch contact. The other end of the momentary switch contact goes to the positive end of the original 6 volt battery.