White Paper: The KCC Scientific Model 1900W-UNV Clock Winder For Standard Electric Clocks
Ken Reindel, KCC Scientific Updated 1-26-13
The purpose of this White Paper is to help provide some background on Standard Electric Time master clock, what a Model 1900W-UNV Clock Winder can do for it, and how the Model 1900W-UNV works.
Historical Perspective. From the 1880s and beyond, inventors became interested in applying the principles of telegraphy to horology. The idea of a battery-wound master clock which would drive multiple slave clocks, effectively communicating the time signal to them, began to take shape. Additionally, it became fascinating to inventors that the “slave” clocks could be very simple with no escapements or springs, no internal batteries, and requiring little if any maintenance. Charles Warner, who founded the Standard Electric Time Company in 1884,1was one such inventor.
Very early on, Standard Electric borrowed heavily from the Self Winding Clock Company for the design of its master clock movements. Master clocks would have the characteristics described above and relied on special contacts to drive the slaves. Later on, this same concept would be extended to driving program wheels and punched tape ribbons within the clocks themselves, to provide bell timing and other electrical sequences to businesses, schools, etc. For example, many such clocks have been found in schoolhouses and were at one time responsible for ringing bells at the proper times throughout different parts of the building to send students to the next class, as well as driving classroom slave clocks.
Standard Electric’s master clock movements eventually took a shape similar to that of the slave clocks: simple, elegant minute impulse ratchet designs for winding the 60, 72, or 80 beat pendulum movements. Originally, banks of large, central remote batteries provided power. Many (but not all) systems were designed to operate from 24 volts. These clocks are found today, often powered by makeshift—and often unsafe–20 to 24 volt power supplies.
A large number of these early Standard Electric clocks wind by way of a pair of electromagnetic coils located at the bottom of the clock movement. The system is very simple. Each revolution of the escape wheel results in electrical contact between a set of points which energize the winding coil once per minute, with pulse duration from 0.5 seconds to sometimes up to 2 seconds per minute depending on the method of commutation employed. This was efficient at the time because of its mechanical simplicity. Energizing the electromagnets pulls a ratchet pawl against a ratchet wheel which increments a mainspring enough to power the clock’s train.
Today we are often approached by customers with clocks that fail due to burned contacts. The clock might run for several hours, days or a month and then mysteriously stop. Also, we are asked if it is possible to “untether” the clock from a power cord, since quite often the owner wants to locate the clock somewhere that is not close to an electrical outlet. Simply connecting a series of batteries to replace the line operated 24 volt power supply results in very poor battery life. Customers try connecting four 6 volt lantern batteries in series to replace the 24 volt power supply that came with the clock.
What would be battery life be in this case? Think back at the minute wind cycle that lasts over 1 second for each impulse (“contact dwell”). This means that the battery is connected to the coil for over 1.7 percent of the time (1 out of every 60 seconds, which is 1/60thof the time or 1.7%). A typical 24 volt winding coil might draw up to 80mA from the battery. For purposes of winding these clocks, typical lantern battery has a useful capacity of about 10 amp-hours. Battery life can therefore be calculated:
Life, in Hours = 10 amp-hours/1.7% of .08 amps= < 7300 hours
There are 8760 hours in a year, so the FOUR lantern batteries would have to be changed at least every 10 months or so. With an average cost of $10 per lantern battery, this would equate to about $50 per year! In addition, where would you mount four lantern batteries in a typical Standard Electric clock?
The Model 1900W-UNV. The Model 1900W-UNV is an innovative new way to wind your minute impulse Standard Electric master clock, available as either a module or No. 6 kit. See illustrations below. On the inside, the kit uses four alkaline D cells and a highly efficient, adaptive voltage regulator that is pulsed on exactly once per minute. The device senses the resistance of the coil and automatically adapts the output voltage to the proper level required by the clock. The output of the Winder is connected directly to the clock coil. The movements are similar to the one shown below.
The trick to delivering long battery life is the length of the pulse, which is internally controlled to exactly
0.3 seconds—much shorter than the mechanical pulse which will be more than 1 second long. The 0.3 second long pulse is more than adequate to assure positive winding of the clock. In addition, since the internal electronics is regulated, the battery energy is more efficiently utilized. The result: over 1 year of battery life with four alkaline D cells (replaceable for about $5 per year—a $45 savings in cost per year vs. the lantern solution), a more convenient battery changing schedule, and elimination of bulky, hazardous, non-original power supplies that were added to the clock somewhere along the way.
The most important benefit is that the 1900W-UNV is connected directly to the clock coil, bypassing contacts. The result is elimination of a common source of failure—burned, pitted or misadjusted contacts! “
NOTE: The Model 1900W-UNV is intended for impulse wind Standard Electric clocks with coils located at the bottom of the movement as shown to the left. It is not intended for clocks with large motors which power gearboxes to pull chains, cords, and weights to run the clock. These are sometimes called “Automatic Reset” clocks and must be line powered.
More pictures and historical information on Standard Electric clocks can be found at:
Many thanks to Jeffrey Wood for his fabulous, timeless collection of pictures and detailed descriptions of these clocks, some of which we reference here.
Model 1900W-UNV Module (Wall power adapter optional) Model 1900W-UNV Kit (includes internal batteries)
Questions and Answers about the Model 1900W-UNV Clock Winder
- I have a minute impulse wind Standard Electric Clock with a transformer and power plug. Do I have to remove these items from the clock in order to use the Model 1900W-UNV? Do I need to remove the contacts?No changes need to be made to the clock. The output of the 1900W-UNV simply needs to be connected directly to the clock coil in place of the wires already there. The 1900W-UNV takes care of the rest. NOTE: Do not plug the clock’s old power supply into the wall with the 1900W-UNV connected. Simply leave the power cord disconnected. If you wish, you can remove the old power supply from the clock but this is not necessary. We recommend you leave the contacts and other devices in place, in the event that someone down the road prefers to operate the clock from line power again.If you wish, you can adjust the contacts so they do not commutate with the escape wheel, but this is not necessary.
- Why don’t I connect the 1900W-UNV in place of the clock’s internal wall-powered circuit?Because the 1900W contains the timing elements to excite the winding coil exactly every minute, there is no need to use the contacts on the clock. In fact, using the contacts will not work since the 1900W—not the contacts–governs when and how long the coils are excited.
- What is the difference between the Model 1900W and the Model 1900W-UNV?The original Model 1900W was a fixed voltage device. The Model 1900W-UNV is our Universal Winder for minute and half-minute impulse-wound clocks of USA manufacture such as Stromberg, Standard Electric, IBM, ITR, Cincinnati Time, Fred Frick-Landis, etc. It was designed to automatically detect the voltage required by the clock and apply the correct drive to the coil. It is revolutionary because you don’t have to worry about the required voltage. It will drive any master or slave clock from 1.5 volts to 25 volts—automatically, correctly, and efficiently. This eliminates confusion in getting the right power source for the clock. Given the broad number of clock voltages in existence, this is quite important.The Model 1900W-UNV also has a mode to drive 30 second impulse clocks. The Model 1900W-UNV replaces all previous 1900W-xV fixed voltage units.
- What is the Model 1900W-UNVR?In a sense, the Model 1900W-UNVR is internationally universal! However, it is NOT required for clocks of USA manufacture. Let’s explain.Most European impulse-wound clocks, such as Magneta, the German companies TN and Siemens, and others require reversing drive. These clocks are often designed with a permanent magnet somewhere in the motor with an armature that must be both attracted and repelled if it is to advance. Clocks manufactured in the USA did not do this, and so they do not require reversing drive. But many if not most impulse-wound clocks manufactured in Europe require reversing drive.The Model 1900W-UNVR is the same as the 1900W-UNV except the output drive reverses from one minute to the next. For example, at 12:05pm let’s assume the drive outputs a positive signal to advance the clock. At 12:06, it outputs a negative signal to advance the clock. At 12:07pm, it once again outputs a positive signal, and so on.Because the output circuitry to do this is more complex, it is a somewhat more costly product than the Model 1900W-UNV.If you have a clock of European manufacture and you think it requires reversing drive but aren’t sure, you are safe to select a Model 1900W-UNVR. If it turns out it does not require reversing drive, the Model 1900W-UNVR will run the clock fine anyhow. No harm will come from driving a non-reversing drive clock with a Model 1900W-UNVR. However, a clock requiring reversing drive will NOT run with the 1900W-UNV. It follows then that if you are not sure where your clock was manufactured, you would be safest to select the Model 1900W-UNVR.Like the Model 1900W-UNV, the Model 1900W-UNVR also has a mode to drive 30 second impulse clocks built in and very easily selectable.
- What kind of wire do I use to connect the 1900W-UNV products?We provide wire sufficient to connect the clock, if the 1900W is placed on top of the clock. If you want to place the 1900W kit on the bottom of the clock and therefore need longer wire, let us know and we can provide additional wire. Our wire is vintage-looking cloth covered wire so that the system blends in with the look of the clock.
- How do I manually wind the clock, say, if it had been previously unwound?There is a button on top of the 1900W Clock Winder which, when depressed, will automatically wind the clock. This button can be pressed multiple times until the clock is wound sufficiently to run.Typically, you would want to wind the clock with 60 impulses to fully wind, but fewer are fine, too. We suggest at least 40 impulses to get things started.
- Is it possible for the clock to unwind itself despite being run by the 1900W-UNV?For clocks with a 59 tooth ratchet wheel (many of the clocks out there), there is no realistic way it will ever unwind itself with a 1900W-UNV. For clocks with a 60 tooth ratchet wheel, if the clock is poorly adjusted and runs, say, 10 minutes per month fast, the clock may unwind before the batteries need to be replaced. But what use is a clock if it is left to run at such a rate? Most enthusiasts will regulate the clock quite closely.Should the clock unwind, it will obviously stop, and the winder will bring it back to fully wound in a matter of less than one hour if left undisturbed. Should this happen, restart the clock.
- Can the 1900W-UNV be used to regulate the clock?It is interesting to note that the extreme high accuracy of the 1900W-UNV can be used to “pace” the clock to timing perfection. The second hand is observed at each audible winding. The pendulum can be adjusted so that over the course of time, the second hand is pointing to the exact same place on the seconds dial every time the clock winds. When this is achieved, the clock will be timed in at a rate of better than 2 seconds per week! Granted, this will take substantial trial and error with most pendulum clocks.
- What about minute impulse Stromberg clocks, or ITR models? These are difficult to wind. Can I use the 1900W-UNV to wind them?Many Stromberg of Chicago movements, such as the Model 45, are also minute wound designs much like the Standard Electric models. The most popular we’ve seen has 10 volt coils but we have also seen 15 volt, 20 volt masters—all of which can be wound with the Model 1900W-UNV without worrying about which voltage clock you have.
- What about clocks that require DC voltages above 25 volts?The Model 1900W-UNV services the majority of the clocks we encounter by far. Although substantially less common, we do run across 40 volt, 80 volt or 110 volt DC movements manufactured by Stromberg, ITR and others. We also offer the Models 1900W-40V, 1900W-80V, and 1900W-110V for these movements. The 1900W-110V is very exciting because it eliminates a potentially very dangerous wiring condition often found in 110 volt DC clocks resulting from unqualified folks attempting to directly rectify the power line, and inadvertently connecting the “live” side of the power cord to exposed metal on the clock! This should be avoided as it creates a VERY DANGEROUS CONDITION! The Model 1900W-110V mitigates this risk.
- I have a weight driven Standard Electric master clock that is wound by a 120 volt AC motor. Can I battery operate this model?Not with our products. Models with 120 volt, 240 volt, or 24 volt AC or DC electric motors cannot be powered by any KCC products. These must continue to be operated from line power. The Model 1900W-UNV is intended only for minute impulse wind clocks with two coils located at the bottom of the movement.
- Will the escape wheel experience abnormal wear as a result of using the 1900W-UNV?No! Let’s compare the two scenarios. Consider first the clock run from the 24 volt supply, and the coil energized with mechanical actuation. With Standard Electric masters, the contacts are set to energize at or during escapement impulse. At some point, the movement becomes fully wound. Because there is no clutch arrangement on the movement, eventually there is forward impulse between the winding mechanism and the train when the clock winds, resulting in strain to the escape wheel teeth. This is especially true since the escape wheel could be forced forward during drop depending on the contact setting in a particular clock. With mechanical actuation through a contact set to energize at escapement impulse, the same tooth will experience wear, every time for all time.With the 1900W-UNV, it is virtually impossible for the clock coils to be energized with the same escape wheel tooth in the same position, every time, for all time. It would be unimaginable that the movement would run at the exact same rate as the 1900W-UNV, no matter how well the movement were adjusted or timed in. Natural drift in the movement timekeeping due to temperature, humidity, etc. will mean that the winding impulse most likely occurs across multiple escape wheel teeth over the course of time, which will tend to lessen the wear or distribute it more evenly, not increase it. Further, statistically it will occur during escapement lock for some portion of the wind cycles when using the 1900W-UNV (which it cannot in the previous case), again reducing potential for wear, and does not depend on how the switch is adjusted.Further, because the actual impulse lasts about 4 times shorter than with mechanical actuation, the time during which this force is applied is lessened very significantly. This statistically results in less wear to the escape wheel than with the mechanical arrangement.
- Can the 1900W family be used to impulse ribbon and wheel program mechanisms and circuits?The Model 1900W-UNV was designed for customers wishing to run their clocks from battery power, using them as timekeeping devices. We can also provide other battery products for enthusiasts wishing to reproduce complete signaling systems, master/slave arrangements, etc. But that is not the intention of this product.In theory, it is possible for an enthusiast to impulse ribbon and wheel program mechanisms with the 1900W-UNV. However, this must be done with great care, and it is advisable to contact Ken’s Clock Clinic for consultation. You can also use the 1900W-UNV to drive a distribution relay that in turn can then drive program units and other things, but an auxiliary power supply would likely be needed to handle the additional load.
- Can the 1900W-UNV be used to drive slave clocks?Absolutely! The Model 1900W-UNV is very popular for driving slave clocks. The minute impulses are very accurate short term and cumulatively. Our typical timekeeping performance when driving slave clocks is on the order of 1 second per week. Our Model 1900W-UNV will drive any slave clock from 1.5 volts to 24 volts. No special setup or wiring is necessary. It automatically detects the required voltage.
- Can I power the 1900W-UNV with a lantern battery?The modular version of the 1900W-UNV is very versatile. It can be used with lantern batteries such as Energizer 528 or 529, four alkaline D batteries (using the supplied battery holder), or can be run from our optional ES-6 EnergyStar wall power adapter.The 1900W-UNV No. 6 Kit runs on four D batteries installed internally, which can be replaced when needed. Battery life is exactly the same whether you use the 1900W-UNV module with an external batteries or the No. 6 Kit version with four internal alkaline D batteries.
- What if I decide I don’t want the 1900W-UNV to impulse the clock?Many, although not all, Standard Electric master units have a contact system connected directly between the verge and the escape wheel. These clocks have the advantage of a relatively short mechanical impulse time, which conserves battery power reasonably well if adjusted correctly. We manufacture a product called the Model 1900-24V Kit which looks just like the 1900W-UNV Kit but outputs a continuous 24 volt DC level. Battery life will be reduced substantially due to contact dwell as described previously, but it will operate in this mode for an estimated run time of 4-5 months between battery changes. We would be happy to exchange your Model 1900W-UNV Clock Winder with the 1900-24V Kit if you prefer. But, we doubt you will ever give up your Model 1900W-UNV Clock Winder once you try it.
- Does the 1900W family save energy?
Absolutely! Most transformer powered clocks use older iron core transformers that are extremely inefficient. They will waste up to 10 watts, possibly more, plugged in all the time. This amounts to around 90KW-Hrs of energy usage per year! At $.12 per kilowatt-hour, it costs almost $11 to keep the clock plugged in per year, which is twice as expensive as changing batteries.
Keep in mind that power supplies found with the early Standard Electric and Stromberg clocks were later add-ons by enthusiasts. These were not part of the clocks originally. We find many of them in unsafe condition today, creating risk of fire or shock. BE CAREFUL with these old power supplies.
As always, Ken’s Clock Clinic and KCC Scientific encourage you to dispose of spent batteries responsibly. Collection areas are available in most communities for this purpose. And, of course, NEVER dispose of alkaline batteries in a fire.