In this paper we analyze the convergence of the following type of series  $$\begin{eqnarray}T_{N}^{{\mathcal{L}}}f(x)=\mathop{\sum }_{j=N_{1}}^{N_{2}}v_{j}\big(e^{-a_{j+1}{\mathcal{L}}}f(x)-e^{-a_{j}{\mathcal{L}}}f(x)\big),\quad x\in \mathbb{R}^{n},\end{eqnarray}$$
$$\begin{eqnarray}T_{N}^{{\mathcal{L}}}f(x)=\mathop{\sum }_{j=N_{1}}^{N_{2}}v_{j}\big(e^{-a_{j+1}{\mathcal{L}}}f(x)-e^{-a_{j}{\mathcal{L}}}f(x)\big),\quad x\in \mathbb{R}^{n},\end{eqnarray}$$ ${\{e^{-t{\mathcal{L}}}\}}_{t>0}$ is the heat semigroup of the operator
${\{e^{-t{\mathcal{L}}}\}}_{t>0}$ is the heat semigroup of the operator  ${\mathcal{L}}=-\unicode[STIX]{x1D6E5}+V$ with
${\mathcal{L}}=-\unicode[STIX]{x1D6E5}+V$ with  $\unicode[STIX]{x1D6E5}$ being the classical laplacian, the nonnegative potential
$\unicode[STIX]{x1D6E5}$ being the classical laplacian, the nonnegative potential  $V$ belonging to the reverse Hölder class
$V$ belonging to the reverse Hölder class  $RH_{q}$ with
$RH_{q}$ with  $q>n/2$ and
$q>n/2$ and  $n\geqslant 3$,
$n\geqslant 3$,  $N=(N_{1},N_{2})\in \mathbb{Z}^{2}$ with
$N=(N_{1},N_{2})\in \mathbb{Z}^{2}$ with  $N_{1}<N_{2}$,
$N_{1}<N_{2}$,  ${\{v_{j}\}}_{j\in \mathbb{Z}}$ is a bounded real sequences, and
${\{v_{j}\}}_{j\in \mathbb{Z}}$ is a bounded real sequences, and  ${\{a_{j}\}}_{j\in \mathbb{Z}}$ is an increasing real sequence.
${\{a_{j}\}}_{j\in \mathbb{Z}}$ is an increasing real sequence.
Our analysis will consist in the boundedness, in  $L^{p}(\mathbb{R}^{n})$ and in
$L^{p}(\mathbb{R}^{n})$ and in  $BMO(\mathbb{R}^{n})$, of the operators
$BMO(\mathbb{R}^{n})$, of the operators  $T_{N}^{{\mathcal{L}}}$ and its maximal operator
$T_{N}^{{\mathcal{L}}}$ and its maximal operator  $T^{\ast }f(x)=\sup _{N}T_{N}^{{\mathcal{L}}}f(x)$.
$T^{\ast }f(x)=\sup _{N}T_{N}^{{\mathcal{L}}}f(x)$.
It is also shown that the local size of the maximal differential transform operators (with  $V=0$) is the same with the order of a singular integral for functions
$V=0$) is the same with the order of a singular integral for functions  $f$ having local support. Moreover, if
$f$ having local support. Moreover, if  ${\{v_{j}\}}_{j\in \mathbb{Z}}\in \ell ^{p}(\mathbb{Z})$, we get an intermediate size between the local size of singular integrals and Hardy–Littlewood maximal operator.
${\{v_{j}\}}_{j\in \mathbb{Z}}\in \ell ^{p}(\mathbb{Z})$, we get an intermediate size between the local size of singular integrals and Hardy–Littlewood maximal operator.