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Digital clocks how to#

She needs to make sure she has the right time on both her digital and analogue clocks.īetsy looks at the digital clock on her wall. The video follows Betsy the Beaver who needs to get ready to go to a friend’s house. Video 1: Helping Betsy the Beaver Tell Time Understand the time terms “o’clock” and “thirty.”Ģ Videos to Help You Teach Common Core Standard: 1.MD.3īelow we provide and breakdown two videos to help you teach your students this standard.Relate analogue clock time to digital clock time, and vice versa.Draw a minute and hour hands on a clock to the half hour and hour interval.Tell time at least to the half hour and hour interval.Recall the number of minutes in a half hour hour.Recall the number of minutes in an hour.Differentiate between the hour and minute hand on an analog clock.Differentiate between an analogue and digital clock.Students who understand this principle can: MD.1).Ĭommon Core Standard: 1.MD.3 - Tell and write time in hours and half-hours using analog and digital clocks. And further on, they will solve word problems involving addition and subtraction of time intervals in minutes (3.

They will learn to tell and write time to the nearest minute and measure time intervals in minutes. Later, your students will learn to tell and write time from analog and digital clocks to the nearest five minutes, both a.m. While reading a clock may be new to most students, this 1st grade skill expands their understanding of the aspects of time they were exposed to in Kindergarten. However, in Kindergarten, they were exposed to aspects of time such as morning, afternoon, and evening. This will be the first standard that students will be learning that specifically addresses time on clocks. There are no common core standards for telling time on clocks in Kindergarten. Then, we provide a breakdown of the specific steps in the videos to help you teach your class.

Below we show two videos that demonstrate this standard.

Digital clocks how to#

The diode will have a band painted on one end - this band should be the end connected to the resistor.Learning how to tell and write time on both a digital and analogue clock is a first grade, Common Core math skill: 1.MD.3. The 1-K-ohm resistor makes sure that the current to the zener diode is limited so we do not burn out the diode.

This is perfect for clocking the TTL counters. The zener diode therefore turns a 10-volt sine wave into a clipped wave oscillating between 0 and 5 volts. A zener diode is also a one-way valve, but it also passes electrons in the other direction if they are above a certain voltage. A diode is a one-way valve for electrons.

The resistor and the zener diode extract a 60-Hz signal from the transformer's sine wave.

The 7805 and capacitors are wired just like they were in the electronic gates article.

There is no polarity to an AC transformer, so it does not matter which transformer lead you connect to which AC lead of the rectifier. One of the terminals on the rectifier will be marked with a "+" - from that you can find the minus and AC inputs.

We use the bridge rectifier to convert the AC to DC.

If you want to use your volt-ohm meter to measure the voltage of an AC transformer, be sure you use an AC voltage range rather than a DC range.

The difference between the AC transformer we are using here and the DC transformer we used in the article on gates is that the AC transformer preserves the 60-Hz sine wave found in 120-volt household current.

Therefore, we need the following parts for our power supply: That means that we want an AC rather than a DC transformer, and we will use a part called a bridge rectifier to convert the AC to DC. For our clock, we want to do things slightly differently because we are going to extract our 60-Hz timebase from the power line. That time, we used a standard wall transformer that produced DC (direct current) power and then regulated it to 5 volts using a 7805. We built one in the electronic gates article. The first thing we need is a power supply. If you have already played around with gates as described in that article, then the description here will make a lot more sense. In particular, the electronic gates article introduces you to TTL chips, breadboards and power supplies. To understand these steps, you will need to have read How Boolean Logic Works and How Electronic Gates Work. Here we will build just the "seconds" part of the clock, but you can easily extend things to build a complete clock with hours, minutes and seconds. The best way to understand the different components of a digital clock and how they work together is to actually walk through the steps of building your own clock.